Synthesis of and compositions containing diaminoacetals and diaminoketals

ABSTRACT

The present invention relates to the reduction of polycyano compounds to produce polyamines, in particular diaminoacetal and diaminoketal compounds, and their use as curing agents in epoxy resin compositions. The reduction with molecular hydrogen can be carried out using a metal catalyst selected from GROUP VIII and a catalytic promoter. The reduction can include anhydrous or aqueous ammonia. The reaction can be carried out in continuous and batch modes with catalyst and solvent recycling. The epoxy resin composition consisting of an epoxy resin and a polyamine curing agent that can be used in fiber-reinforced composite materials, coating materials, and the like.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application claims the priority benefit from U.S. ProvisionalPatent Application No. 61/655,794, filed Jun. 5, 2012, entitled“Processes for the Preparation of Di-(2-aminoethyl) Formal,Di-(3-aminopropyl) Formal, and Related Molecules,” which is incorporatedherein in its entirety.

BACKGROUND

The present invention generally relates to chemical synthesis ofpolyamine compounds, in particular chemical synthesis diaminoacetal anddiaminoketal compounds, and compositions containing these compounds anduses of the these compositions.

BRIEF SUMMARY OF THE INVENTION

In one aspect, the present invention provides a process for preparing apolyamine compound represented by Formula (1) from a polycyano compoundrepresented by Formula (2):

wherein: each of R¹ and R² is independently selected from the groupconsisting of hydrogen, alkyl group, cycloalkyl group and aromaticgroup; both of R¹ and R² can form a cyclic radical; each of R³, R⁴, R⁵and R⁶ is independently selected from the group consisting of hydrogen,alkyl group, cycloalkyl group and aromatic group; R³ and R⁴ can combinewith each other to form a cyclic radical; R⁵ and R⁶ can combine witheach other to form a cyclic radical; and each m and n is independentlyan integer ranging from 1 to 20. In one embodiment, the processcomprises reducing the polycyano compound of Formula (2) with a reducingagent to produce the polyamine compound of Formula (1). In oneembodiment, the reducing agent comprises molecular hydrogen. In oneembodiment, the reduction is carried out in the presence of a catalyst.In one embodiment, the catalyst comprises one or more Group VIII metals.In one embodiment, the catalyst comprises one or more Group VIII metalsselected from the group consisting of nickel, palladium, platinum,ruthenium, rhodium and cobalt.

In another aspect, the present invention provides an epoxy resincomposition for fiber-reinforced composite materials, for coatingmaterials, for encapsulating materials, and/or adhesives. In oneembodiment, the epoxy resin composition comprises an epoxy resin; and anamine curing agent, the amine curing agent comprising a polyaminecompound having Formula (1):

wherein: each of R¹ and R² is independently selected from the groupconsisting of hydrogen, alkyl group, cycloalkyl group and aromaticgroup; or both of R¹ and R² forms a cyclic radical; each of R³, R⁴, R⁵and R⁶ is independently selected from the group consisting of hydrogen,alkyl group, cycloalkyl group and aromatic group; R³ and R⁴ can combinewith each other to form a cyclic radical; R⁵ and R⁶ can combine witheach other to form a cyclic radical; and each m and n is independentlyan integer ranging from 1 to 20. In one embodiment, the epoxy resincomprises an average of at least two epoxide groups per molecule. In oneembodiment, the epoxy resin has two epoxide groups per molecule (adiepoxide epoxy resin). In one embodiment, the diepoxide epoxy resin isselected from the group consisting of glycidyl ether epoxy resin,glycidyl ester epoxy resin, glycidyl amine epoxy resin, alicyclic epoxyresin, aliphatic epoxy resin, and phenolic epoxy resin.

In another aspect, the present invention provides a method of curing anepoxy resin formulation. In one embodiment, the method of curing anepoxy resin formulation cures the epoxy resin to a degree of cure of atleast about 50% or more. In one embodiment, the curing of the epoxyresin formulation comprises heating the epoxy resin formulation. In oneembodiment, the method of curing the epoxy resin formulation comprises(i) providing an epoxy resin composition in accordance with the presentinvention; and (ii) heating the epoxy resin composition. In oneembodiment, the method of curing the epoxy resin formulation furtherincludes adding a reinforcing agent to produce a reinforced cured epoxyresin composition.

In another aspect, the present invention provides a cross-linked polymermatrix in which the cross-linked polymer is derived from an epoxy resinhaving at least two epoxide groups and a cross-linking group derivedfrom a curing agent represented by Formula (1):

wherein: each of R¹ and R² is independently selected from the groupconsisting of hydrogen, alkyl group, cycloalkyl group and aromaticgroup; both of R¹ and R² can form a cyclic radical; each of R³, R⁴, R⁵and R⁶ is independently selected from the group consisting of hydrogen,alkyl group, cycloalkyl group and aromatic group; R³ and R⁴ can combinewith each other to form a cyclic radical; R⁵ and R⁶ can combine witheach other to form a cyclic radical; and each m and n is independentlyan integer ranging from 0 to 20. In one embodiment, the epoxy resin hastwo epoxide per molecule. In one embodiment, the epoxy resin is selectedfrom the group consisting of glycidyl ether epoxy resin, glycidyl esterepoxy resin, glycidyl amine epoxy resin, alicyclic epoxy resin,aliphatic epoxy resin, phenolic epoxy resin, and combinations thereof.

In another aspect, the present invention provides a method for recyclinga reinforced composite in accordance with the present invention. In oneembodiment, the method for recycling the reinforced composite comprisesa step of degrading the cross-linked polymer matrix using an acid. Inone embodiment, the degradation of the cross-linked polymer matrix iscarried out using an acid in the presence of a solvent. In oneembodiment, the degradation of the cross-linked polymer matrix iscarried out using an acid under a heating condition.

In another aspect, the present invention relates to a degradationproduct resulting from the method for recycling the reinforced compositeaccording to the present invention.

In another aspect, the present invention relates to the use of any ofthe epoxy compositions of the present invention as an adhesive, acoating material, or an encapsulating material; wherein the epoxycomposition can be removed, recycled, or dissolved from the article incontact with said epoxy composition via the method of degrading theepoxy composition according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows structures of BPADGE and Diamino acetal C-14 of Example 14;

FIG. 2 shows a generic scheme for the conversion of polycyano compoundsof Formula (2) into polyamino compounds of Formula (1);

FIG. 3 shows generic cross-linked epoxy product and generic epoxydegradation product; and

FIG. 4 shows examples of epoxy resins that can be used in accordancewith exemplary embodiments of the present invention.

DETAILED DESCRIPTION

The present subject matter will now be described more fully hereinafterwith reference to the accompanying Figures and Examples, in whichrepresentative embodiments are shown. The present subject matter can,however, be embodied in different forms and should not be construed aslimited to the embodiments set forth herein. Rather, these embodimentsare provided to describe and enable one of skill in the art. Unlessotherwise defined, all technical and scientific terms used herein havethe same meaning as commonly understood by one of ordinary skill in theart to which the subject matter pertains. All publications, patentapplications, patents, and other references mentioned herein areincorporated by reference in their entirety.

In an aspect, the present invention relates to diaminoacetals, toprocesses for their preparation, and especially to their preparationfrom dicyanoacetals. The over-all process of this invention includes twosteps. In the first step, dicyanoacetals are prepared by the reaction ofa compound containing both an alcohol group and a cyano group (now,herein referred to a cyanohydrin) with an aldehyde or ketone, (or analdehyde or ketone equivalent). In the second step the dicyanoacetal ishydrogenated to give the corresponding diaminoacetal. The primaryembodiment of the present invention is the preparation of diaminoacetalcompounds from dicyanoacetal compounds.

I. Process for Making Polyamines

The present invention provides an efficient process for the preparationof the polyamine compound represented by Formula (1):

from a polycyano compound of Formula (2):

wherein: each of R¹ and R² is independently selected from the groupconsisting of hydrogen, alkyl group, cycloalkyl group and aromaticgroup; or both of R¹ and R² forms a cyclic radical; each of R³, R⁴, R⁵and R⁶ is independently selected from the group consisting of hydrogen,alkyl group, cycloalkyl group and aromatic group; R³ and R⁴ can combinewith each other to form a cyclic radical; R⁵ and R⁶ can combine witheach other to form a cyclic radical; and each m and n is independentlyan integer ranging from 1 to 20; the process comprising reducing thecompound of Formula (2) with a reducing agent to produce the compound ofFormula (1).

Formula (1) represents a class of polyamine molecules that depending onthe exact nature of R¹ and R² can be subdivided into three classes: (i)polyaminoformal (R¹=H; and R²=H); (ii) polyaminoacetal (e.g., R¹=H; andR²=carbon fragment); and (ii) polyaminoketal (e.g., R¹=carbon fragment;and R²=carbon fragment). Individually, the molecules classifiedaccording to Formula (1) may contain an acetal group, ketal group, or aformal group, that connects the polyamine groups.

Referring to the compounds of Formulas (1) and (2), in one embodiment,each of R¹ and R² is independently an alkyl group. In one embodiment,each of R¹ and R² is independently a C₁-C₂₀ alkyl group. In oneembodiment, each of R¹ and R² is independently a C₁-C₁₅ alkyl group. Inone embodiment, each of R¹ and R² is independently a C₁-C₁₀ alkyl group.In one embodiment, each of R¹ and R² is independently a C₁-C₅ alkylgroup. In one embodiment, each of R¹ and R² is independently a C₁-C₃alkyl group. In one embodiment, each of R¹ and R² is independently aC₁-C₂ alkyl group. In one embodiment, each of R¹ and R² is independentlya C₁ alkyl group. In one embodiment, each of R¹ and R² is independentlyselected from the group consisting of C₁ (e.g., methyl); C₂ (e.g.,ethyl); C₃ (e.g., propyl); C₄ (e.g., n-butyl & isobutyl); C₅ (e.g.,pentyl, isopentyl, neopentyl); and C₆ (e.g., hexyl, 2-Methylpentyl;3-Methylpentyl; 2,3-Dimethylbutyl; 2,2-Dimethylbutyl). In oneembodiment, each of R¹ and R² is independent selected from the groupconsisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl,tert-butyl, amyl, isoamyl, pentyl, sec-butyl, isopentyl, neopentyl,heptyl, hexyl, octyl, decyl, dodecyl, and hexadecyl. In one embodiment,each of R¹ and R² is independent selected from the group consisting ofmethyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl,decyl, undecyl, dodecyl, hexadecyl, and icosyl.

In one embodiment, each of R¹ and R² is independently a cycloalkylgroup. In one embodiment, each of R¹ and R² is independently acycloalkyl group. In one embodiment, each of R¹ and R² is independentlya C₃-C₂₀ cycloalkyl group. In one embodiment, each of R¹ and R² isindependently a C₃-C₁₅ cycloalkyl group. In one embodiment, each of R¹and R² is independently a C₃-C₁₀ cycloalkyl group. In one embodiment,each of R¹ and R² is independently a C₃-C₅ cycloalkyl group. In oneembodiment, each of R¹ and R² is independently selected from the groupconsisting of cyclopropylalkyl (e.g., cyclopropylmethyl),cyclobutylalkyl (e.g., cyclobutylmethyl), cyclopentylalkyl (e.g.cyclopentylmethyl), cyclohexylalkyl (e.g. cyclohexylmethyl),cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

In one embodiment, each of R¹ and R² is independently an aryl group. Theterm“aryl” as used herein refers to any functional group or substituentderived from an aromatic ring, be it phenyl, naphthyl, thienyl, indolyl,or the like. Examples of aryl include, but are not limited to, phenyl,tolyl, xylyl, naphthyl, biphenylyl, benzyl, and phenylethyl groups.

In one embodiment, both R¹ and R² can form a cyclic group. The cyclicgroup is not particularly limited. It can be a carbocycle, a cycloalkyl,an aryl, a heterocycle, a heteroaryl, an aralkyl or any suitable cyclicgroup. In one embodiment, the cyclic group is selected from the groupconsisting of cycloalkyl, cycloalkyl aryl, heterocyclic, alkylaryl,alkylheterocycle and arylheterocycle groups.

In one embodiment, each of R³, R⁴, R⁵ and R⁶ is independently an alkylgroup.

In one embodiment, each of R³, R⁴, R⁵ and R⁶ is independently a C₁-C₂₀alkyl group. In one embodiment, each of R³, R⁴, R⁵ and R⁶ isindependently a C₁-C₁₅ alkyl group. In one embodiment, each of R³, R⁴,R⁵ and R⁶ is independently a C₁-C₁₀ alkyl group. In one embodiment, eachof R³, R⁴, R⁵ and R⁶ is independently a C₁-C₅ alkyl group. In oneembodiment, each of R³, R⁴, R⁵ and R⁶ is independently a C₁-C₃ alkylgroup. In one embodiment, each of R³, R⁴, R⁵ and R⁶ is independently aC₁-C₂ alkyl group. In one embodiment, each of R³, R⁴, R⁵ and R⁶ isindependently a C₁ alkyl group. In one embodiment, each of R³, R⁴, R⁵and R⁶ is independently selected from the group consisting of C₁ (e.g.,methyl); C₂ (e.g., ethyl); C₃ (e.g., propyl); C₄ (e.g., n-butyl &isobutyl); C₅ (e.g., pentyl, isopentyl, neopentyl); and C₆ (e.g., hexyl,2-Methylpentyl; 3-Methylpentyl; 2,3-Dimethylbutyl; 2,2-Dimethylbutyl).In one embodiment, each of R³, R⁴, R⁵ and R⁶ is independent selectedfrom the group consisting of methyl, ethyl, propyl, isopropyl, butyl,isobutyl, tert-butyl, amyl, isoamyl, pentyl, sec-butyl, isopentyl,neopentyl, heptyl, hexyl, octyl, decyl, dodecyl, and hexadecyl. In oneembodiment, each of R³, R⁴, R⁵ and R⁶ is independent selected from thegroup consisting of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl,octyl, nonyl, decyl, undecyl, dodecyl, hexadecyl, and icosyl.

In one embodiment, each of R³, R⁴, R⁵ and R⁶ is independently acycloalkyl group. In one embodiment, each of R³, R⁴, R⁵ and R⁶ isindependently a cycloalkyl group. In one embodiment, each of R³, R⁴, R⁵and R⁶ is independently a C₃-C₂₀ cycloalkyl group. In one embodiment,each of R¹ and R² is independently a C₃-C₁₅ cycloalkyl group. In oneembodiment, each of R³, R⁴, R⁵ and R⁶ is independently a C₃-C₁₀cycloalkyl group. In one embodiment, each of R³, R⁴, R⁵ and R⁶ isindependently a C₃-C₅ cycloalkyl group. In one embodiment, each of R³,R⁴, R⁵ and R⁶ is independently selected from the group consisting ofcyclopropylalkyl (e.g., cyclopropylmethyl), cyclobutylalkyl (e.g.,cyclobutylmethyl), cyclopentylalkyl (e.g. cyclopentylmethyl),cyclohexylalkyl (e.g. cyclohexylmethyl), cyclopropyl, cyclobutyl,cyclopentyl, and cyclohexyl.

In one embodiment, each of R³, R⁴, R⁵ and R⁶ is independently an arylgroup. As stated elsewhere herein, the term“aryl” refers to anyfunctional group or substituent derived from an aromatic ring, be itphenyl, naphthyl, thienyl, indolyl, or the like. Examples of suitablearyl groups include, but are not limited to, phenyl, tolyl, xylyl,naphthyl, biphenylyl, benzyl, and phenylethyl groups.

In one embodiment, both R³ and R⁴ can combine with each other to form acyclic radical. In one embodiment, both R³ and R⁴ combine with eachother to form a C₃-C₂₀ cycloalkyl group. In one embodiment, both R³ andR⁴ combine with each other to form a C₃-C₁₅ cycloalkyl group. In oneembodiment, both R³ and R⁴ combine with each other to form a C₃-C₁₀cycloalkyl group. In one embodiment, both R³ and R⁴ combine with eachother to form a C₃-C₅ cycloalkyl group. In one embodiment, both R³ andR⁴ combine with each other to form a cyclic group selected from thegroup consisting of cyclopropylalkyl (e.g., cyclopropylmethyl),cyclobutylalkyl (e.g., cyclobutylmethyl), cyclopentylalkyl (e.g.cyclopentylmethyl), cyclohexylalkyl (e.g. cyclohexylmethyl),cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

In one embodiment, R⁵ and R⁶ can combine with each other to form acyclic radical. In one embodiment, both R⁵ and R⁶ can combine with eachother to form a cyclic radical. In one embodiment, both R⁵ and R⁶combine with each other to form a C₃-C₂₀ cycloalkyl group. In oneembodiment, both R⁵ and R⁶ combine with each other to form a C₃-C₁₅cycloalkyl group. In one embodiment, both R⁵ and R⁶ combine with eachother to form a C₃-C₁₀ cycloalkyl group. In one embodiment, both R⁵ andR⁶ combine with each other to form a C₃-C₅ cycloalkyl group. In oneembodiment, both R⁵ and R⁶ combine with each other to form a cyclicgroup selected from the group consisting of cyclopropylalkyl (e.g.,cyclopropylmethyl), cyclobutylalkyl (e.g., cyclobutylmethyl),cyclopentylalkyl (e.g. cyclopentylmethyl), cyclohexylalkyl (e.g.cyclohexylmethyl), cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

Each m and n in the polyamine and polycyano compounds represented byFormulas (1) and (2) is independently an integer ranging from 1 to 20.In one embodiment, each m and n is independently an integer selectedfrom the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,14, 15, 16, 17, 18, 19, and 20.

The process of making the polyamine of Formula (1) from the polycyanoFormula (2) employs a reducing agent. Any suitable reducing agent can beused in this process. In one embodiment, the reducing agent comprisesmolecular hydrogen. In one embodiment, the reduction is carried out atmolecular hydrogen pressure of from about 80 psi to about 3000 psi. Inone embodiment, the reduction is carried out at molecular hydrogenpressure selected from the group consisting of about 80 psi, about 160psi, about 240 psi, about 320 psi, about 400 psi, about 480 psi, about560 psi, about 640 psi, about 720 psi, about 800 psi, about 880 psi,about 960 psi, about 1040 psi, about 1120 psi, about 1200 psi, about1280 psi, about 1360 psi, about 1440 psi, about 1520 psi, about 1600psi, about 1680 psi, about 1760 psi, about 1840 psi, about 1920 psi,about 2000 psi, about 2080 psi, about 2160 psi, about 2240 psi, about2320 psi, about 2400 psi, about 2480 psi, about 2560 psi, about 2640psi, about 2720 psi, about 2800 psi, about 2880 psi, about 2960 psi, andabout 3040 psi. In one embodiment, the reduction is carried out atmolecular hydrogen pressure selected from the group consisting of lessthan about 80 psi, less than about 160 psi, less than about 240 psi,less than about 320 psi, less than about 400 psi, less than about 480psi, less than about 560 psi, less than about 640 psi, less than about720 psi, less than about 800 psi, less than about 880 psi, less thanabout 960 psi, less than about 1040 psi, less than about 1120 psi, lessthan about 1200 psi, less than about 1280 psi, less than about 1360 psi,less than about 1440 psi, less than about 1520 psi, less than about 1600psi, less than about 1680 psi, less than about 1760 psi, less than about1840 psi, less than about 1920 psi, less than about 2000 psi, less thanabout 2080 psi, less than about 2160 psi, less than about 2240 psi, lessthan about 2320 psi, less than about 2400 psi, less than about 2480 psi,less than about 2560 psi, less than about 2640 psi, less than about 2720psi, less than about 2800 psi, less than about 2880 psi, less than about2960 psi, and less than about 3040 psi. In one embodiment, the reductionis carried out at molecular hydrogen pressure of from about 100 psi toabout 1500 psi.

In some embodiments, the reduction is carried out at molecular hydrogenpressure of at least 80 psi. In some embodiments, the reduction iscarried out at molecular hydrogen pressure selected from the groupconsisting of about less than about 1500 psi but equal to or greaterthan about 80 psi, less than about 1450 psi but equal to or greater thanabout 80 psi, less than about 1400 psi but equal to or greater thanabout 80 psi, less than about 1350 psi but equal to or greater thanabout 80 psi, less than about 1300 psi but equal to or greater thanabout 80 psi, less than about 1250 psi but equal to or greater thanabout 80 psi, less than about 1200 psi but equal to or greater thanabout 80 psi, less than about 1150 psi but equal to or greater thanabout 80 psi, less than about 1100 psi but equal to or greater thanabout 80 psi, less than about 1050 psi but equal to or greater thanabout 80 psi, less than about 1000 psi but equal to or greater thanabout 80 psi, less than about 950 psi but equal to or greater than about80 psi, less than about 900 psi but equal to or greater than about 80psi, less than about 850 psi but equal to or greater than about 80 psi,less than about 800 psi but equal to or greater than about 80 psi, lessthan about 750 psi but equal to or greater than about 80 psi, less thanabout 700 psi but equal to or greater than about 80 psi, less than about650 psi but equal to or greater than about 80 psi, less than about 600psi but equal to or greater than about 80 psi, less than about 550 psibut equal to or greater than about 80 psi, less than about 500 psi butequal to or greater than about 80 psi, less than about 450 psi but equalto or greater than about 80 psi, less than about 400 psi but equal to orgreater than about 80 psi, less than about 350 psi but equal to orgreater than about 80 psi, less than about 300 psi but equal to orgreater than about 80 psi, less than about 250 psi but equal to orgreater than about 80 psi, less than about 200 psi but equal to orgreater than about 80 psi, less than about 150 psi but equal to orgreater than about 80 psi, and less than about 100 psi but equal to orgreater than about 80 psi.

In some embodiments, the process of making the polyamine of Formula (1)from the polycyano Formula (2) employs a reducing agent and a catalyst.In one embodiment, the reduction is carried out in the presence of ametal-containing catalyst. In one embodiment, the metal-containingcatalyst comprises one or more Group VIII metal. In one embodiment, thecatalyst contains a metal or pseudometal selected from a groupconsisting of Raney nickel, Sponge nickel, palladium, platinum, cobalt,copper, copper oxide, Lindlar catalyst, rhodium, platinum dioxide,sodium borohydride, lithium aluminum hydride, nickel, ruthenium, iron,tellurium, copper triphenylphosphine complexes, ruthenium phosphinecomplexes, rhodium carbonyl clusters, palladium on carbon, and complexesof palladium with quinoline, pyridine, and phenylisocyano ligands. Inone embodiment, the catalyst contains a metal selected from the groupconsisting of nickel, palladium, platinum, ruthenium, rhodium andcobalt.

When a catalyst is employed in the process of making the polyamine ofFormula (1), any suitable amount of the catalyst can be used. In oneembodiment, the reduction step is carried out in the presence of acatalyst present in an amount ranging from about 0.1 wt. % to about 120wt. % of the polycyano compound of Formula (2). In one embodiment, thereduction step is carried out in the presence of a catalyst present inan amount selected from the group consisting of about 120 wt. % butequal to or greater than about 0.1 wt. %, less than about 115 wt. % butequal to or greater than about 0.1 wt. %, less than about 110 wt. % butequal to or greater than about 0.1 wt. %, less than about 105 wt. % butequal to or greater than about 0.1 wt. %, less than about 100 wt. % butequal to or greater than about 0.1 wt. %, less than about 95 wt. % butequal to or greater than about 0.1 wt. %, less than about 90 wt. % butequal to or greater than about 0.1 wt. %, less than about 85 wt. % butequal to or greater than about 0.1 wt. %, less than about 80 wt. % butequal to or greater than about 0.1 wt. %, less than about 75 wt. % butequal to or greater than about 0.1 wt. %, less than about 70 wt. % butequal to or greater than about 0.1 wt. %, less than about 65 wt. % butequal to or greater than about 0.1 wt. %, less than about 60 wt. % butequal to or greater than about 0.1 wt. %, less than about 55 wt. % butequal to or greater than about 0.1 wt. %, less than about 50 wt. % butequal to or greater than about 0.1 wt. %, less than about 45 wt. % butequal to or greater than about 0.1 wt. %, less than about 40 wt. % butequal to or greater than about 0.1 wt. %, less than about 35 wt. % butequal to or greater than about 0.1 wt. %, less than about 30 wt. % butequal to or greater than about 0.1 wt. %, less than about 25 wt. % butequal to or greater than about 0.1 wt. %, less than about 20 wt. % butequal to or greater than about 0.1 wt. %, less than about 15 wt. % butequal to or greater than about 0.1 wt. %, less than about 10 wt. % butequal to or greater than about 0.1 wt. %, and less than about 5 wt. %but equal to or greater than about 0.1 wt. %, wherein the percentagesare wt. % of the polycyano compound of Formula (2).

In one embodiment, the reduction step is carried out in the presence ofa catalyst present in an amount selected from the group consisting ofabout 0.1 wt. %, about 0.2 wt. %, about 0.3 wt. %, about 0.4 wt. %,about 0.5 wt. %, about 0.6 wt. %, about 0.7 wt. %, about 0.8 wt. %,about 0.9 wt. %, about 1 wt. %, about 1.1 wt. %, about 1.2 wt. %, about1.3 wt. %, about 1.4 wt. %, about 1.5 wt. %, about 1.6 wt. %, about 1.7wt. %, about 1.8 wt. %, about 1.9 wt. %, about 2 wt. %, about 2.1 wt. %,about 2.2 wt. %, about 2.3 wt. %, about 2.4 wt. %, about 2.5 wt. %,about 2.6 wt. %, about 2.7 wt. %, about 2.8 wt. %, about 2.9 wt. %,about 3 wt. %, about 3.1 wt. %, about 3.2 wt. %, about 3.3 wt. %, about3.4 wt. %, about 3.5 wt. %, about 3.6 wt. %, about 3.7 wt. %, about 3.8wt. %, about 3.9 wt. %, about 4 wt. %, about 4.1 wt. %, about 4.2 wt. %,about 4.3 wt. %, about 4.4 wt. %, about 4.5 wt. %, about 4.6 wt. %,about 4.7 wt. %, about 4.8 wt. %, about 4.9 wt. %, about 5 wt. %, about5.1 wt. %, about 5.2 wt. %, about 5.3 wt. %, about 5.4 wt. %, about 5.5wt. %, about 5.6 wt. %, about 5.7 wt. %, about 5.8 wt. %, about 5.9 wt.%, about 6 wt. %, about 6.1 wt. %, about 6.2 wt. %, about 6.3 wt. %,about 6.4 wt. %, about 6.5 wt. %, about 6.6 wt. %, about 6.7 wt. %,about 6.8 wt. %, about 6.9 wt. %, about 7 wt. %, about 7.1 wt. %, about7.2 wt. %, about 7.3 wt. %, about 7.4 wt. %, about 7.5 wt. %, about 7.6wt. %, about 7.7 wt. %, about 7.8 wt. %, about 7.9 wt. %, about 8 wt. %,about 8.1 wt. %, about 8.2 wt. %, about 8.3 wt. %, about 8.4 wt. %,about 8.5 wt. %, about 8.6 wt. %, about 8.7 wt. %, about 8.8 wt. %,about 8.9 wt. %, about 9 wt. %, about 9.1 wt. %, about 9.2 wt. %, about9.3 wt. %, about 9.4 wt. %, about 9.5 wt. %, about 9.6 wt. %, about 9.7wt. %, about 9.8 wt. %, about 9.9 wt. %, about 10 wt. %, about 10.1 wt.%, about 10.2 wt. %, about 10.3 wt. %, about 10.4 wt. %, about 10.5 wt.%, about 10.6 wt. %, about 10.7 wt. %, about 10.8 wt. %, about 10.9 wt.%, about 11 wt. %, about 11.1 wt. %, about 11.2 wt. %, about 11.3 wt. %,about 11.4 wt. %, about 11.5 wt. %, about 11.6 wt. %, about 11.7 wt. %,about 11.8 wt. %, about 11.9 wt. %, about 12 wt. %, about 12.1 wt. %,about 12.2 wt. %, about 12.3 wt. %, about 12.4 wt. %, about 12.5 wt. %,about 12.6 wt. %, about 12.7 wt. %, about 12.8 wt. %, about 12.9 wt. %,about 13 wt. %, about 13.1 wt. %, about 13.2 wt. %, about 13.3 wt. %,about 13.4 wt. %, about 13.5 wt. %, about 13.6 wt. %, about 13.7 wt. %,about 13.8 wt. %, about 13.9 wt. %, about 14 wt. %, about 14.1 wt. %,about 14.2 wt. %, about 14.3 wt. %, about 14.4 wt. %, about 14.5 wt. %,about 14.6 wt. %, about 14.7 wt. %, about 14.8 wt. %, about 14.9 wt. %,about 15 wt. %, about 15.1 wt. %, about 15.2 wt. %, about 15.3 wt. %,about 15.4 wt. %, about 15.5 wt. %, about 15.6 wt. %, about 15.7 wt. %,about 15.8 wt. %, about 15.9 wt. %, about 16 wt. %, about 16.1 wt. %,about 16.2 wt. %, about 16.3 wt. %, about 16.4 wt. %, about 16.5 wt. %,about 16.6 wt. %, about 16.7 wt. %, about 16.8 wt. %, about 16.9 wt. %,about 17 wt. %, about 17.1 wt. %, about 17.2 wt. %, about 17.3 wt. %,about 17.4 wt. %, about 17.5 wt. %, about 17.6 wt. %, about 17.7 wt. %,about 17.8 wt. %, about 17.9 wt. %, about 18 wt. %, about 18.1 wt. %,about 18.2 wt. %, about 18.3 wt. %, about 18.4 wt. %, about 18.5 wt. %,about 18.6 wt. %, about 18.7 wt. %, about 18.8 wt. %, about 18.9 wt. %,about 19 wt. %, about 19.1 wt. %, about 19.2 wt. %, about 19.3 wt. %,about 19.4 wt. %, about 19.5 wt. %, about 19.6 wt. %, about 19.7 wt. %,about 19.8 wt. %, about 19.9 wt. %, about 20 wt. %, about 20.1 wt. %,about 20.2 wt. %, about 20.3 wt. %, about 20.4 wt. %, about 20.5 wt. %,about 20.6 wt. %, about 20.7 wt. %, about 20.8 wt. %, about 20.9 wt. %,about 21 wt. %, about 21.1 wt. %, about 21.2 wt. %, about 21.3 wt. %,about 21.4 wt. %, about 21.5 wt. %, about 21.6 wt. %, about 21.7 wt. %,about 21.8 wt. %, about 21.9 wt. %, about 22 wt. %, about 22.1 wt. %,about 22.2 wt. %, about 22.3 wt. %, about 22.4 wt. %, about 22.5 wt. %,about 22.6 wt. %, about 22.7 wt. %, about 22.8 wt. %, about 22.9 wt. %,about 23 wt. %, about 23.1 wt. %, about 23.2 wt. %, about 23.3 wt. %,about 23.4 wt. %, about 23.5 wt. %, about 23.6 wt. %, about 23.7 wt. %,about 23.8 wt. %, about 23.9 wt. %, about 24 wt. %, about 24.1 wt. %,about 24.2 wt. %, about 24.3 wt. %, about 24.4 wt. %, about 24.5 wt. %,about 24.6 wt. %, about 24.7 wt. %, about 24.8 wt. %, about 24.9 wt. %,about 25 wt. %, about 25.1 wt. %, about 25.2 wt. %, about 25.3 wt. %,about 25.4 wt. %, about 25.5 wt. %, about 25.6 wt. %, about 25.7 wt. %,about 25.8 wt. %, about 25.9 wt. %, about 26 wt. %, about 26.1 wt. %,about 26.2 wt. %, about 26.3 wt. %, about 26.4 wt. %, about 26.5 wt. %,about 26.6 wt. %, about 26.7 wt. %, about 26.8 wt. %, about 26.9 wt. %,about 27 wt. %, about 27.1 wt. %, about 27.2 wt. %, about 27.3 wt. %,about 27.4 wt. %, about 27.5 wt. %, about 27.6 wt. %, about 27.7 wt. %,about 27.8 wt. %, about 27.9 wt. %, about 28 wt. %, about 28.1 wt. %,about 28.2 wt. %, about 28.3 wt. %, about 28.4 wt. %, about 28.5 wt. %,about 28.6 wt. %, about 28.7 wt. %, about 28.8 wt. %, about 28.9 wt. %,about 29 wt. %, about 29.1 wt. %, about 29.2 wt. %, about 29.3 wt. %,about 29.4 wt. %, about 29.5 wt. %, about 29.6 wt. %, about 29.7 wt. %,about 29.8 wt. %, about 29.9 wt. %, about 30 wt. %, about 30.1 wt. %,about 30.2 wt. %, about 30.3 wt. %, about 30.4 wt. %, about 30.5 wt. %,about 30.6 wt. %, about 30.7 wt. %, about 30.8 wt. %, about 30.9 wt. %,about 31 wt. %, about 31.1 wt. %, about 31.2 wt. %, about 31.3 wt. %,about 31.4 wt. %, about 31.5 wt. %, about 31.6 wt. %, about 31.7 wt. %,about 31.8 wt. %, about 31.9 wt. %, about 32 wt. %, about 32.1 wt. %,about 32.2 wt. %, about 32.3 wt. %, about 32.4 wt. %, about 32.5 wt. %,about 32.6 wt. %, about 32.7 wt. %, about 32.8 wt. %, about 32.9 wt. %,about 33 wt. %, about 33.1 wt. %, about 33.2 wt. %, about 33.3 wt. %,about 33.4 wt. %, about 33.5 wt. %, about 33.6 wt. %, about 33.7 wt. %,about 33.8 wt. %, about 33.9 wt. %, about 34 wt. %, about 34.1 wt. %,about 34.2 wt. %, about 34.3 wt. %, about 34.4 wt. %, about 34.5 wt. %,about 34.6 wt. %, about 34.7 wt. %, about 34.8 wt. %, about 34.9 wt. %,about 35 wt. %, about 35.1 wt. %, about 35.2 wt. %, about 35.3 wt. %,about 35.4 wt. %, about 35.5 wt. %, about 35.6 wt. %, about 35.7 wt. %,about 35.8 wt. %, about 35.9 wt. %, about 36 wt. %, about 36.1 wt. %,about 36.2 wt. %, about 36.3 wt. %, about 36.4 wt. %, about 36.5 wt. %,about 36.6 wt. %, about 36.7 wt. %, about 36.8 wt. %, about 36.9 wt. %,about 37 wt. %, about 37.1 wt. %, about 37.2 wt. %, about 37.3 wt. %,about 37.4 wt. %, about 37.5 wt. %, about 37.6 wt. %, about 37.7 wt. %,about 37.8 wt. %, about 37.9 wt. %, about 38 wt. %, about 38.1 wt. %,about 38.2 wt. %, about 38.3 wt. %, about 38.4 wt. %, about 38.5 wt. %,about 38.6 wt. %, about 38.7 wt. %, about 38.8 wt. %, about 38.9 wt. %,about 39 wt. %, about 39.1 wt. %, about 39.2 wt. %, about 39.3 wt. %,about 39.4 wt. %, about 39.5 wt. %, about 39.6 wt. %, about 39.7 wt. %,about 39.8 wt. %, about 39.9 wt %, about 40 wt. %, about 40.1 wt. %,about 40.2 wt. %, about 40.3 wt. %, about 40.4 wt. %, about 40.5 wt. %,about 40.6 wt. %, about 40.7 wt. %, about 40.8 wt. %, about 40.9 wt. %,about 41 wt. %, about 41.1 wt. %, about 41.2 wt. %, about 41.3 wt. %,about 41.4 wt. %, about 41.5 wt. %, about 41.6 wt. %, about 41.7 wt. %,about 41.8 wt. %, about 41.9 wt. %, about 42 wt. %, about 42.1 wt. %,about 42.2 wt. %, about 42.3 wt. %, about 42.4 wt. %, about 42.5 wt. %,about 42.6 wt. %, about 42.7 wt. %, about 42.8 wt. %, about 42.9 wt. %,about 43 wt. %, about 43.1 wt. %, about 43.2 wt. %, about 43.3 wt. %,about 43.4 wt. %, about 43.5 wt. %, about 43.6 wt. %, about 43.7 wt. %,about 43.8 wt. %, about 43.9 wt. %, about 44 wt. %, about 44.1 wt. %,about 44.2 wt. %, about 44.3 wt. %, about 44.4 wt. %, about 44.5 wt. %,about 44.6 wt. %, about 44.7 wt. %, about 44.8 wt. %, about 44.9 wt. %,about 45 wt. %, about 45.1 wt. %, about 45.2 wt. %, about 45.3 wt. %,about 45.4 wt. %, about 45.5 wt. %, about 45.6 wt. %, about 45.7 wt. %,about 45.8 wt. %, about 45.9 wt. %, about 46 wt. %, about 46.1 wt. %,about 46.2 wt. %, about 46.3 wt. %, about 46.4 wt. %, about 46.5 wt. %,about 46.6 wt. %, about 46.7 wt. %, about 46.8 wt. %, about 46.9 wt. %,about 47 wt. %, about 47.1 wt. %, about 47.2 wt. %, about 47.3 wt. %,about 47.4 wt. %, about 47.5 wt. %, about 47.6 wt. %, about 47.7 wt. %,about 47.8 wt. %, about 47.9 wt. %, about 48 wt. %, about 48.1 wt. %,about 48.2 wt. %, about 48.3 wt. %, about 48.4 wt. %, about 48.5 wt. %,about 48.6 wt. %, about 48.7 wt. %, about 48.8 wt. %, about 48.9 wt. %,about 49 wt. %, about 49.1 wt. %, about 49.2 wt. %, about 49.3 wt. %,about 49.4 wt. %, about 49.5 wt. %, about 49.6 wt. %, about 49.7 wt. %,about 49.8 wt. %, about 49.9 wt. %, about 50 wt. %, about 50.1 wt. %,about 50.2 wt. %, about 50.3 wt. %, about 50.4 wt. %, about 50.5 wt. %,about 50.6 wt. %, about 50.7 wt. %, about 50.8 wt. %, about 50.9 wt. %,about 51 wt. %, about 51.1 wt. %, about 51.2 wt. %, about 51.3 wt. %,about 51.4 wt. %, about 51.5 wt. %, about 51.6 wt. %, about 51.7 wt. %,about 51.8 wt. %, about 51.9 wt. %, about 52 wt. %, about 52.1 wt. %,about 52.2 wt. %, about 52.3 wt. %, about 52.4 wt. %, about 52.5 wt. %,about 52.6 wt. %, about 52.7 wt. %, about 52.8 wt. %, about 52.9 wt. %,about 53 wt. %, about 53.1 wt. %, about 53.2 wt. %, about 53.3 wt. %,about 53.4 wt. %, about 53.5 wt. %, about 53.6 wt. %, about 53.7 wt. %,about 53.8 wt. %, about 53.9 wt. %, about 54 wt. %, about 54.1 wt. %,about 54.2 wt. %, about 54.3 wt. %, about 54.4 wt. %, about 54.5 wt. %,about 54.6 wt. %, about 54.7 wt. %, about 54.8 wt. %, about 54.9 wt. %,about 55 wt. %, about 55.1 wt. %, about 55.2 wt. %, about 55.3 wt. %,about 55.4 wt. %, about 55.5 wt. %, about 55.6 wt. %, about 55.7 wt. %,about 55.8 wt. %, about 55.9 wt. %, about 56 wt. %, about 56.1 wt. %,about 56.2 wt. %, about 56.3 wt. %, about 56.4 wt. %, about 56.5 wt. %,about 56.6 wt. %, about 56.7 wt. %, about 56.8 wt. %, about 56.9 wt. %,about 57 wt. %, about 57.1 wt. %, about 57.2 wt. %, about 57.3 wt. %,about 57.4 wt. %, about 57.5 wt. %, about 57.6 wt. %, about 57.7 wt. %,about 57.8 wt. %, about 57.9 wt. %, about 58 wt. %, about 58.1 wt. %,about 58.2 wt. %, about 58.3 wt. %, about 58.4 wt. %, about 58.5 wt. %,about 58.6 wt. %, about 58.7 wt. %, about 58.8 wt. %, about 58.9 wt. %,about 59 wt. %, about 59.1 wt. %, about 59.2 wt. %, about 59.3 wt. %,about 59.4 wt. %, about 59.5 wt. %, about 59.6 wt. %, about 59.7 wt. %,about 59.8 wt. %, about 59.9 wt. %, about 60 wt. %, about 60.1 wt. %,about 60.2 wt. %, about 60.3 wt. %, about 60.4 wt. %, about 60.5 wt. %,about 60.6 wt. %, about 60.7 wt. %, about 60.8 wt. %, about 60.9 wt. %,about 61 wt. %, about 61.1 wt. %, about 61.2 wt. %, about 61.3 wt. %,about 61.4 wt. %, about 61.5 wt. %, about 61.6 wt. %, about 61.7 wt. %,about 61.8 wt. %, about 61.9 wt. %, about 62 wt. %, about 62.1 wt. %,about 62.2 wt. %, about 62.3 wt. %, about 62.4 wt. %, about 62.5 wt. %,about 62.6 wt. %, about 62.7 wt. %, about 62.8 wt. %, about 62.9 wt. %,about 63 wt. %, about 63.1 wt. %, about 63.2 wt. %, about 63.3 wt. %,about 63.4 wt. %, about 63.5 wt. %, about 63.6 wt. %, about 63.7 wt. %,about 63.8 wt. %, about 63.9 wt. %, about 64 wt. %, about 64.1 wt. %,about 64.2 wt. %, about 64.3 wt. %, about 64.4 wt. %, about 64.5 wt. %,about 64.6 wt. %, about 64.7 wt. %, about 64.8 wt. %, about 64.9 wt. %,about 65 wt. %, about 65.1 wt. %, about 65.2 wt. %, about 65.3 wt. %,about 65.4 wt. %, about 65.5 wt. %, about 65.6 wt. %, about 65.7 wt. %,about 65.8 wt. %, about 65.9 wt. %, about 66 wt. %, about 66.1 wt. %,about 66.2 wt. %, about 66.3 wt. %, about 66.4 wt. %, about 66.5 wt. %,about 66.6 wt. %, about 66.7 wt. %, about 66.8 wt. %, about 66.9 wt. %,about 67 wt. %, about 67.1 wt. %, about 67.2 wt. %, about 67.3 wt. %,about 67.4 wt. %, about 67.5 wt. %, about 67.6 wt. %, about 67.7 wt. %,about 67.8 wt. %, about 67.9 wt. %, about 68 wt. %, about 68.1 wt. %,about 68.2 wt. %, about 68.3 wt. %, about 68.4 wt. %, about 68.5 wt. %,about 68.6 wt. %, about 68.7 wt. %, about 68.8 wt. %, about 68.9 wt. %,about 69 wt. %, about 69.1 wt. %, about 69.2 wt. %, about 69.3 wt. %,about 69.4 wt. %, about 69.5 wt. %, about 69.6 wt. %, about 69.7 wt. %,about 69.8 wt. %, about 69.9 wt. %, about 70 wt. %, about 70.1 wt. %,about 70.2 wt. %, about 70.3 wt. %, about 70.4 wt. %, about 70.5 wt. %,about 70.6 wt. %, about 70.7 wt. %, about 70.8 wt. %, about 70.9 wt. %,about 71 wt. %, about 71.1 wt. %, about 71.2 wt. %, about 71.3 wt. %,about 71.4 wt. %, about 71.5 wt. %, about 71.6 wt. %, about 71.7 wt. %,about 71.8 wt. %, about 71.9 wt. %, about 72 wt. %, about 72.1 wt. %,about 72.2 wt. %, about 72.3 wt. %, about 72.4 wt. %, about 72.5 wt. %,about 72.6 wt. %, about 72.7 wt. %, about 72.8 wt. %, about 72.9 wt. %,about 73 wt. %, about 73.1 wt. %, about 73.2 wt. %, about 73.3 wt. %,about 73.4 wt. %, about 73.5 wt. %, about 73.6 wt. %, about 73.7 wt. %,about 73.8 wt. %, about 73.9 wt. %, about 74 wt. %, about 74.1 wt. %,about 74.2 wt. %, about 74.3 wt. %, about 74.4 wt. %, about 74.5 wt. %,about 74.6 wt. %, about 74.7 wt. %, about 74.8 wt. %, about 74.9 wt. %,about 75 wt. %, about 75.1 wt. %, about 75.2 wt. %, about 75.3 wt. %,about 75.4 wt. %, about 75.5 wt. %, about 75.6 wt. %, about 75.7 wt. %,about 75.8 wt. %, about 75.9 wt. %, about 76 wt. %, about 76.1 wt. %,about 76.2 wt. %, about 76.3 wt. %, about 76.4 wt. %, about 76.5 wt. %,about 76.6 wt. %, about 76.7 wt. %, about 76.8 wt. %, about 76.9 wt. %,about 77 wt. %, about 77.1 wt. %, about 77.2 wt. %, about 77.3 wt. %,about 77.4 wt. %, about 77.5 wt. %, about 77.6 wt. %, about 77.7 wt. %,about 77.8 wt. %, about 77.9 wt. %, about 78 wt. %, about 78.1 wt. %,about 78.2 wt. %, about 78.3 wt. %, about 78.4 wt. %, about 78.5 wt. %,about 78.6 wt. %, about 78.7 wt. %, about 78.8 wt. %, about 78.9 wt. %,about 79 wt. %, about 79.1 wt. %, about 79.2 wt. %, about 79.3 wt. %,about 79.4 wt. %, about 79.5 wt. %, about 79.6 wt. %, about 79.7 wt. %,about 79.8 wt. %, about 79.9 wt. %, about 80 wt. %, about 80.1 wt. %,about 80.2 wt. %, about 80.3 wt. %, about 80.4 wt. %, about 80.5 wt. %,about 80.6 wt. %, about 80.7 wt. %, about 80.8 wt. %, about 80.9 wt. %,about 81 wt. %, about 81.1 wt. %, about 81.2 wt. %, about 81.3 wt. %,about 81.4 wt. %, about 81.5 wt. %, about 81.6 wt. %, about 81.7 wt. %,about 81.8 wt. %, about 81.9 wt. %, about 82 wt. %, about 82.1 wt. %,about 82.2 wt. %, about 82.3 wt. %, about 82.4 wt. %, about 82.5 wt. %,about 82.6 wt. %, about 82.7 wt. %, about 82.8 wt. %, about 82.9 wt. %,about 83 wt. %, about 83.1 wt. %, about 83.2 wt. %, about 83.3 wt. %,about 83.4 wt. %, about 83.5 wt. %, about 83.6 wt. %, about 83.7 wt. %,about 83.8 wt. %, about 83.9 wt. %, about 84 wt. %, about 84.1 wt. %,about 84.2 wt. %, about 84.3 wt. %, about 84.4 wt. %, about 84.5 wt. %,about 84.6 wt. %, about 84.7 wt. %, about 84.8 wt. %, about 84.9 wt. %,about 85 wt. %, about 85.1 wt. %, about 85.2 wt. %, about 85.3 wt. %,about 85.4 wt. %, about 85.5 wt. %, about 85.6 wt. %, about 85.7 wt. %,about 85.8 wt. %, about 85.9 wt. %, about 86 wt. %, about 86.1 wt. %,about 86.2 wt. %, about 86.3 wt. %, about 86.4 wt. %, about 86.5 wt. %,about 86.6 wt. %, about 86.7 wt. %, about 86.8 wt. %, about 86.9 wt. %,about 87 wt. %, about 87.1 wt. %, about 87.2 wt. %, about 87.3 wt. %,about 87.4 wt. %, about 87.5 wt. %, about 87.6 wt. %, about 87.7 wt. %,about 87.8 wt. %, about 87.9 wt. %, about 88 wt. %, about 88.1 wt. %,about 88.2 wt. %, about 88.3 wt. %, about 88.4 wt. %, about 88.5 wt. %,about 88.6 wt. %, about 88.7 wt. %, about 88.8 wt. %, about 88.9 wt. %,about 89 wt. %, about 89.1 wt. %, about 89.2 wt. %, about 89.3 wt. %,about 89.4 wt. %, about 89.5 wt. %, about 89.6 wt. %, about 89.7 wt. %,about 89.8 wt. %, about 89.9 wt. %, about 90 wt. %, about 90.1 wt. %,about 90.2 wt. %, about 90.3 wt. %, about 90.4 wt. %, about 90.5 wt. %,about 90.6 wt. %, about 90.7 wt. %, about 90.8 wt. %, about 90.9 wt. %,about 91 wt. %, about 91.1 wt. %, about 91.2 wt. %, about 91.3 wt. %,about 91.4 wt. %, about 91.5 wt. %, about 91.6 wt. %, about 91.7 wt. %,about 91.8 wt. %, about 91.9 wt. %, about 92 wt. %, about 92.1 wt. %,about 92.2 wt. %, about 92.3 wt. %, about 92.4 wt. %, about 92.5 wt. %,about 92.6 wt. %, about 92.7 wt. %, about 92.8 wt. %, about 92.9 wt. %,about 93 wt. %, about 93.1 wt. %, about 93.2 wt. %, about 93.3 wt. %,about 93.4 wt. %, about 93.5 wt. %, about 93.6 wt. %, about 93.7 wt. %,about 93.8 wt. %, about 93.9 wt. %, about 94 wt. %, about 94.1 wt. %,about 94.2 wt. %, about 94.3 wt. %, about 94.4 wt. %, about 94.5 wt. %,about 94.6 wt. %, about 94.7 wt. %, about 94.8 wt. %, about 94.9 wt. %,about 95 wt. %, about 95.1 wt. %, about 95.2 wt. %, about 95.3 wt. %,about 95.4 wt. %, about 95.5 wt. %, about 95.6 wt. %, about 95.7 wt. %,about 95.8 wt. %, about 95.9 wt. %, about 96 wt. %, about 96.1 wt. %,about 96.2 wt. %, about 96.3 wt. %, about 96.4 wt. %, about 96.5 wt. %,about 96.6 wt. %, about 96.7 wt. %, about 96.8 wt. %, about 96.9 wt. %,about 97 wt. %, about 97.1 wt. %, about 97.2 wt. %, about 97.3 wt. %,about 97.4 wt. %, about 97.5 wt. %, about 97.6 wt. %, about 97.7 wt. %,about 97.8 wt. %, about 97.9 wt. %, about 98 wt. %, about 98.1 wt. %,about 98.2 wt. %, about 98.3 wt. %, about 98.4 wt. %, about 98.5 wt. %,about 98.6 wt. %, about 98.7 wt. %, about 98.8 wt. %, about 98.9 wt. %,about 99 wt. %, about 99.1 wt. %, about 99.2 wt. %, about 99.3 wt. %,about 99.4 wt. %, about 99.5 wt. %, about 99.6 wt. %, about 99.7 wt. %,about 99.8 wt. %, about 99.9 wt. %, about 100 wt. %, about 100.1 wt. %,about 100.2 wt. %, about 100.3 wt. %, about 100.4 wt. %, about 100.5 wt.%, about 100.6 wt. %, about 100.7 wt. %, about 100.8 wt. %, about 100.9wt. %, about 101 wt. %, about 101.1 wt. %, about 101.2 wt. %, about101.3 wt. %, about 101.4 wt. %, about 101.5 wt. %, about 101.6 wt. %,about 101.7 wt. %, about 101.8 wt. %, about 101.9 wt. %, about 102 wt.%, about 102.1 wt. %, about 102.2 wt. %, about 102.3 wt. %, about 102.4wt. %, about 102.5 wt. %, about 102.6 wt. %, about 102.7 wt. %, about102.8 wt. %, about 102.9 wt. %, about 103 wt. %, about 103.1 wt. %,about 103.2 wt. %, about 103.3 wt. %, about 103.4 wt. %, about 103.5 wt.%, about 103.6 wt. %, about 103.7 wt. %, about 103.8 wt. %, about 103.9wt. %, about 104 wt. %, about 104.1 wt. %, about 104.2 wt. %, about104.3 wt. %, about 104.4 wt. %, about 104.5 wt. %, about 104.6 wt. %,about 104.7 wt. %, about 104.8 wt. %, about 104.9 wt. %, about 105 wt.%, about 105.1 wt. %, about 105.2 wt. %, about 105.3 wt. %, about 105.4wt. %, about 105.5 wt. %, about 105.6 wt. %, about 105.7 wt. %, about105.8 wt. %, about 105.9 wt. %, about 106 wt. %, about 106.1 wt. %,about 106.2 wt. %, about 106.3 wt. %, about 106.4 wt. %, about 106.5 wt.%, about 106.6 wt. %, about 106.7 wt. %, about 106.8 wt. %, about 106.9wt. %, about 107 wt. %, about 107.1 wt. %, about 107.2 wt. %, about107.3 wt. %, about 107.4 wt. %, about 107.5 wt. %, about 107.6 wt. %,about 107.7 wt. %, about 107.8 wt. %, about 107.9 wt. %, about 108 wt.%, about 108.1 wt. %, about 108.2 wt. %, about 108.3 wt. %, about 108.4wt. %, about 108.5 wt. %, about 108.6 wt. %, about 108.7 wt. %, about108.8 wt. %, about 108.9 wt. %, about 109 wt. %, about 109.1 wt. %,about 109.2 wt. %, about 109.3 wt. %, about 109.4 wt. %, about 109.5 wt.%, about 109.6 wt. %, about 109.7 wt. %, about 109.8 wt. %, about 109.9wt. %, about 110 wt. %, about 110.1 wt. %, about 110.2 wt. %, about110.3 wt. %, about 110.4 wt. %, about 110.5 wt. %, about 110.6 wt. %,about 110.7 wt. %, about 110.8 wt. %, about 110.9 wt. %, about 111 wt.%, about 111.1 wt. %, about 111.2 wt. %, about 111.3 wt. %, about 111.4wt. %, about 111.5 wt. %, about 111.6 wt. %, about 111.7 wt. %, about111.8 wt. %, about 111.9 wt. %, about 112 wt. %, about 112.1 wt. %,about 112.2 wt. %, about 112.3 wt. %, about 112.4 wt. %, about 112.5 wt.%, about 112.6 wt. %, about 112.7 wt. %, about 112.8 wt. %, about 112.9wt. %, about 113 wt. %, about 113.1 wt. %, about 113.2 wt. %, about113.3 wt. %, about 113.4 wt. %, about 113.5 wt. %, about 113.6 wt. %,about 113.7 wt. %, about 113.8 wt. %, about 113.9 wt. %, about 114 wt.%, about 114.1 wt. %, about 114.2 wt. %, about 114.3 wt. %, about 114.4wt. %, about 114.5 wt. %, about 114.6 wt. %, about 114.7 wt. %, about114.8 wt. %, about 114.9 wt. %, about 115 wt. %, about 115.1 wt. %,about 115.2 wt. %, about 115.3 wt. %, about 115.4 wt. %, about 115.5 wt.%, about 115.6 wt. %, about 115.7 wt. %, about 115.8 wt. %, about 115.9wt. %, about 116 wt. %, about 116.1 wt. %, about 116.2 wt. %, about116.3 wt. %, about 116.4 wt. %, about 116.5 wt. %, about 116.6 wt. %,about 116.7 wt. %, about 116.8 wt. %, about 116.9 wt. %, about 117 wt.%, about 117.1 wt. %, about 117.2 wt. %, about 117.3 wt. %, about 117.4wt. %, about 117.5 wt. %, about 117.6 wt. %, about 117.7 wt. %, about117.8 wt. %, about 117.9 wt. %, about 118 wt. %, about 118.1 wt. %,about 118.2 wt. %, about 118.3 wt. %, about 118.4 wt. %, about 118.5 wt.%, about 118.6 wt. %, about 118.7 wt. %, about 118.8 wt. %, about 118.9wt. %, about 119 wt. %, about 119.1 wt. %, about 119.2 wt. %, about119.3 wt. %, about 119.4 wt. %, about 119.5 wt. %, about 119.6 wt. %,about 119.7 wt. %, about 119.8 wt. %, about 119.9 wt. %, and about 120wt. % of the polycyano compound of Formula (2).

In some embodiments, the process of making the polyamine of Formula (1)from the polycyano Formula (2) employs a reducing agent, a catalyst anda catalyst promoter. The term “catalyst promoter” as used hereinincludes any substances which themselves are not catalysts, but whenmixed in small quantities with a catalyst increase the efficiency of thecatalyst. In one embodiment, the catalyst promoter comprises one or moretrace metals. In one embodiment, the catalyst promoter comprises one ormore trace metals selected from the group consisting of Fe, Co, Mn, Mg,Al, Ni, Mo, Cu, Pd, and Pt. In one embodiment, the catalyst promotercomprises one or more trace metals selected from the group consisting ofiron, chromium, molybdenum, and vanadium. In one embodiment, thecombination of catalyst and catalyst promoter is provided as a singlecomposition. In one embodiment, the combination of catalyst and catalystpromoter comprises Sponge Ni/Mo Catalyst and Fe/Cr as the promoter(e.g., A-4000 available from Johnson Matthey, West Depford, N.J., USA).

In an embodiment, the acid-labile polyamines of type Formula (1), may befurther chemically modified prior to being incorporated into epoxycompositions.

In some embodiments, the process of making the polyamine of Formula (1)from the polycyano Formula (2) employs a suitable temperature condition.In one embodiment, the reduction is carried out at a temperature of fromabout 15° C. to about 200° C. In one embodiment, the reduction iscarried out at a temperature of from about 20° C. to about 120° C. Inone embodiment, the reduction is carried out at a temperature selectedfrom the group consisting of about 15° C., about 25° C., about 35° C.,about 45° C., about 55° C., about 65° C., about 75° C., about 85° C.,about 95° C., about 100° C., about 100° C., about 105° C., about 115°C., about 125° C., about 135° C., about 145° C., about 155° C., about165° C., about 175° C., about 185° C., about 195° C., and about 200° C.In one embodiment, the reduction is carried out at a temperatureselected from the group consisting of about 15° C., less than about 25°C., less than about 35° C., less than about 45° C., less than about 55°C., less than about 65° C., less than about 75° C., less than about 85°C., less than about 95° C., less than about 100° C., less than about100° C., less than about 105° C., less than about 115° C., less thanabout 125° C., less than about 135° C., less than about 145° C., lessthan about 155° C., less than about 165° C., less than about 175° C.,less than about 185° C., less than about 195° C., and less than about200° C.

In some embodiments, the reduction is carried out at a temperatureselected from the group consisting of about 15° C. to about 120° C.,about 15° C. to about 110° C., about 15° C. to about 100° C., about 15°C. to about 90° C., about 15° C. to about 80° C., about 15° C. to about70° C., about 15° C. to about 60° C., about 15° C. to about 50° C.,about 15° C. to about 40° C., about 20° C. to about 30° C., and about20° C. to about 25° C.

In some embodiments, the process of making the polyamine of Formula (1)from the polycyano Formula (2) employs ammonia. In one embodiment, thereduction is carried out in the presence of anhydrous ammonia. In oneembodiment, the reduction is carried out in the presence of aqueousammonia. In one embodiment, the ammonia is recycled ammonia. In oneembodiment, the reduction is carried out in the presence of ammonia inan amount of from about 1 mole to about 40 moles per mole of thecompound of Formula (2) used. In one embodiment, the reduction iscarried out in the presence of ammonia in an amount of about 2 moles,about 3 moles, about 4 moles, about 5 moles, about 10 moles, about 15moles, about 20 moles, about 25 moles, about 30 moles, about 35 moles,or about 40 moles per mole of the compound of Formula (2) used.

In some embodiments, the process of making the polyamine of Formula (1)from the polycyano Formula (2) employs a solvent. Any suitable solventmay be used. In one embodiment, the reduction is carried out in thepresence of a solvent selected from the group consisting of methanol,ethanol, tetrahydrofuran, dioxane and combinations thereof. In oneembodiment, the solvent is recycled.

In some embodiments, the process of making the polyamine of Formula (1)from the polycyano Formula (2) is carried out in a batch reactor. In oneembodiment, the reduction is carried out in a continuous reactor. In oneembodiment, the reduction is carried out in continuous reactor selectedfrom the group consisting of a flow reactor, a continuous stirred tankreactor, a trickle bed reactor, a fixed bed reactor, a loop reactor, abubble reactor, a tube reactor, a pipe reactor, and a slurry reactor.

In some preferred embodiment, the reduction of the polycyano Formula (2)is carried out at a temperature of from about 20° C. to about 120° C.and at molecular hydrogen pressure of from about 80 psi to about 1500psi. In some preferred embodiment, the reduction of the polycyanoFormula (2) is carried out at a temperature of from about 20° C. toabout 120° C. and at molecular hydrogen pressure of from about 100 psito about 1500 psi. In some preferred embodiments, the reduction of thepolycyano of Formula (2) is carried out at a temperature of from about20° C. to about 80° C. and at molecular hydrogen pressure of from about600 psi to about 1000 psi.

Exemplary polyamine compounds represented by Formula (1) include, butare not limited to, the following:

Exemplary polycyano compounds represented by Formula (2) include, butare not limited to, the following:

II. Compositions and Method of Use

The present invention provides epoxy resin compositions for reinforcedcomposite materials also well as for other epoxy applications, includingcoating, adhesives, and encapsulates. In some embodiments, the epoxycompositions are serviceable for both fiber-reinforced and non-fiberreinforced composite materials. In one embodiment, the epoxy resincomposition comprises an epoxy resin; and a polyamine curing agentcomprising a compound having Formula (1):

Formula (1)

wherein: each of R¹ and R² is independently selected from the groupconsisting of hydrogen, alkyl group, cycloalkyl group and aromaticgroup; both of R¹ and R² can form a cyclic radical; each of R³, R⁴, R⁵,and R⁶ is independently selected from the group consisting of hydrogen,alkyl group, cycloalkyl group and aromatic group; R³ and R⁴ can combinewith each other to form a cyclic radical; R⁵ and R⁶ can combine witheach other to form a cyclic radical; and each m and n is independentlyan integer ranging from 1 to 20.

In one embodiment, the epoxy resin composition comprises an epoxy resinthat has an average of at least two epoxide groups per molecule. In oneembodiment, the epoxy resin composition comprises a diepoxide resin. Inone embodiment, the epoxy resin composition comprises a diepoxide resinselected from a group consisting of glycidyl ether epoxy resin, glycidylester epoxy resin, glycidyl amine epoxy resin, alicyclic epoxy resin,aliphatic epoxy resin, phenolic epoxy resin, and combinations thereof.

In some embodiments, the epoxy resin composition comprises an epoxyresin that comprises a blend of epoxy resins. In one embodiment, theepoxy resin composition comprises a blend of bisphenol-based epoxyresins. In one embodiment, the epoxy resin composition comprises a blendof bisphenol-based epoxy resins having an epoxide equivalent weight(EEW) in the range of 160 to 220. In one embodiment, the epoxy resincomposition comprises a blend of bisphenol-based epoxy resins having anepoxide equivalent weight (EEW) in the range of 400 to 1500.

Generally, epoxy resin's epoxide equivalent weight (EEW) is defined bythe following equation 1 (eq. 1):

$\begin{matrix}{{{Epoxy}\mspace{14mu} {resing}\mspace{14mu} {epoxide}\mspace{14mu} {{eq}.\mspace{14mu} {wt}.\; \left( {{or}\mspace{14mu} {EEW}} \right)}} = \frac{{MW}\mspace{14mu} {of}\mspace{14mu} {epoxy}\mspace{14mu} {resin}}{{{no}.\mspace{11mu} {of}}\mspace{14mu} {epoxides}\mspace{14mu} {in}\mspace{14mu} {the}\mspace{14mu} {epoxy}\mspace{14mu} {resin}}} & \left( {{eq}.\mspace{14mu} 1} \right)\end{matrix}$

wherein MW of epoxy resin represents molecular weight of the of epoxyresin.

Analogously, amine hydrogen equivalent weight is defined by thefollowing equation 2 (eq. 2):

$\begin{matrix}{{{EpoxyAmine}\mspace{14mu} {hydrogen}\mspace{11mu} {{eq}.\mspace{11mu} {wt}.\; \left( {{or}\mspace{14mu} {AEW}} \right)}} = \frac{{MW}\mspace{14mu} {of}\mspace{14mu} {amine}}{{{no}.\mspace{11mu} {of}}\mspace{14mu} {active}\mspace{14mu} {hydrogens}}} & \left( {{eq}.\mspace{14mu} 2} \right)\end{matrix}$

wherein MW of amine represents molecular weight of the of the amine.

The stoichiometric ratio of an amine hardener to use with epoxy resinhaving a known or calculable epoxide equivalent weight EEW can becalculated using the following equation 3 (eq. 3):

$\begin{matrix}{{{stoichiometric}\mspace{14mu} {ratio}\mspace{14mu} {of}\mspace{14mu} {amine}} = \frac{{Amine}\mspace{14mu} H\mspace{14mu} {{eq}.\mspace{11mu} {wt}} \times 100}{{Epoxide}\mspace{14mu} {{eq}.\mspace{14mu} {wt}.\mspace{14mu} {of}}\mspace{14mu} {resin}}} & \left( {{eq}.\mspace{14mu} 3} \right)\end{matrix}$

As, an example, EEW of bisphenol A diglycidyl ether (BPADGE), AEW ofdiamino acetal of Example 14 (diamino acetal C-14), and stoichiometricratio of diamino acetal C-14 are calculated as follows.

Referring to FIG. 1, diamine acetal C-14 has a molecular weight of129.24 atomic mass units (amu) and four active hydrogens. According toeq. 2, AEW of diamine acetal C-14 equals 32.31 (or 129.24÷4). BPADGE hasa molecular weight of 340.41 amu and two epoxides. According to eq. 1,EEW of BPADGE equals 170.205 (or 340.41÷2). According to eq. 3, thestoichiometric ratio of diamine acetal C-14 to use with BPADGE equals18.98 (or [32.31×100]÷170.205). In other words, if one wishes to use astoichiometric amount of diamine acetal C-14 with BPADGE, one would need18.98 parts diamine acetal C-14 by wt. per 100 parts resin (BPADGE) or18.98 g of diamine acetal C-14 for every 100 g of BPADGE used.

In some embodiments, epoxy resins may be blended, filled, or modifiedwith reactive and non-reactive components. In one such embodiment, itmay be necessary to adjust the concentration of the curing polyamineagent to cure only the portion of the mix that is reactive; e.g., theresins and any reactive diluent present. In one embodiment, this may bedone by calculating the epoxide equivalent weight (EEW) of the total mixand then applying equation 2 (eq. 2) to determine the amount of curingpolyamine agent to add to 100 parts of the epoxy resin formulation. Asan example, an EEW of a blended epoxy resins may be calculated accordingto equation 4 (eq. 4).

$\begin{matrix}{{{EEW}\mspace{14mu} {of}\mspace{14mu} {mix}} = \frac{{Total}\mspace{14mu} {{Wt}.\mspace{11mu} {of}}\mspace{14mu} {Mix}}{\frac{Wta}{EEWa} + \frac{Wtb}{EEWb} + \ldots + \frac{Wtn}{EEWn}}} & \left( {{eq}.\mspace{14mu} 4} \right)\end{matrix}$

wherein Total Wt. of Mix represents the molecular weight of the totalmix and includes all materials, both reactive and non-reactive; a, b, .. . and n, are only the materials reactive with the polyamine curingagent and are characterised by an epoxy ring; EEWa represents EEW ofreactive material a; EEWb represents EEW of reactive material b; andEEWn represents EEW of reactive material n.

In some embodiments of the present invention, the epoxy resincomposition includes a blended epoxy resin, and a polyamine curing agentof Formula (1) as can be calculated by eq. 3. In one embodiment, epoxyresin blend includes a mixture of a diglycidyl ether of a bisphenol,especially bisphenol A, having an EEW of 150-195, typically 180-190, anda diglycidyl ether of a bisphenol, especially bisphenol A having an EEWof 400-1500, preferably 1200-1400. In one embodiment, epoxy resin blendincludes a mixture of a diglycidyl ether of a bisphenol, especiallybisphenol A, having an EEW of 150-195, typically 180-190, a diglycidylether of a bisphenol, especially bisphenol A, having an EEW of 400-1500,preferably 1200-1400, and an epoxy phenolic novalac resin with afunctionality of 2.2 to 4, typically 3.6 or above, having an EEW of170-190, preferably 174-180. In one embodiment, epoxy resin blendincludes a mixture of a diglycidyl ether of a bisphenol, especiallybisphenol A, having an EEW of 150-195, typically 176, a diglycidyl etherof a bisphenol, typically bisphenol A, having an EEW of 400-1500,preferably 1200-1400, and a tetra-functional epoxy having an EEW of117-134.

Various bisphenol-based epoxy resins may be used for the presentinvention. In particular, in one embodiment the bisphenol-based epoxyresin is an intermediate molecule based on the reaction ofepichlorohydrin and bisphenol A (“BPA”) and/or bisphenol F (“BPF”).Bisphenol-based epoxy resins that are useful for the present inventioninclude, but are not limited to, bisphenol A diglycidyl ether,(“BPADGE”) and its oligomers and bisphenol F diglycidyl ether,(“BPFDGE”) and its oligomers. FIG. 4 depicts various epoxy resinsincluding generic structures for BPADGE and BPFDGE and their oligomers.In some embodiments, molecular weight of preferred oligomers of BPADGEand BPFDGE can be up to approximately 6000 g/mol. In one embodiment, thebisphenol-based epoxy resin based on bisphenol A has a molecular weightin the range of about 340 to about 6000 g/mol. In one embodiment, thebisphenol-based epoxy resin based on bisphenol F has a molecular weightin the range of about 310 to about 6000 g/mol. In some embodiments, thebisphenol-based epoxy resins have a molecular weight between andoptionally including any two of the following values: 298, 300, 310,340, 400, 600, 800, 1000, 1200, 1500, 1800, 2100, 2400, 2700, 3000,3300, 3600, 3900, 4200, 4500, 4800, 5100, 5400, and 6000. Since thebisphenol-based epoxy resins have 2 epoxy groups per oligomer, thebisphenol-based epoxy resins have an epoxide equivalent weight (EEW)that is generally about half of the molecular weight of the oligomer. Inone embodiment, the bisphenol-based epoxy resin is present from about 40to about 95 wt %, based on the combined weight of the bisphenol-basedepoxy resin, amine curing agent, and multi-epoxy reactive diluent. Inanother embodiment, the bisphenol-based epoxy resin is present fromabout 40 to about 95 wt %, based on the combined weight of thecomponents in the curable composition. In some embodiments, thebisphenol-based epoxy resin is present in an amount between andoptionally including any two of the following values: 40, 45, 50, 55,60, 65, 70, 75, 80, 85, 90, and 95 wt %, based on the combined weight ofthe components in the curable composition.

Examples of commercially available bisphenol A diglycidyl ether epoxyresins are Insulcast 503/504 BLK; Insulcast 504 Clear; Insulcast 125;Insulcast 333; Insulcast 136; and Insulcast 502, available (from ITWPolymer Technologies (Glenview, Ill., U.S.A.); Epon 828, and Epon 826available from Hexion Specialty Chemicals, Inc., now Momentive SpecialtyChemicals, Inc., part of Momentive Performance Materials Holdings, Inc.,(Columbus, Ohio, U.S.A.). Examples of commercially available bisphenol Fdiglycidyl ether epoxy resins are Araldite® GY285, Araldite® GY281, andAraldite® PY302-2 from Huntsman International, LLC (Salt Lake City,Utah, USA). Mixtures of bisphenol-based epoxy resins can be used in thecurable composition.

In some embodiments, less than stoichiometric amount of polyamine curingagent of Formula (1) is used in the epoxy resin composition inaccordance with the present invention. In one embodiment, the epoxyresin composition contains 2% of the stoichiometric amount of polyaminecuring agent of Formula (1). In one embodiment, the epoxy resincomposition contains the polyamine curing agent of Formula (1) in apercentage selected from the group consisting of about 4%, about 6%,about 8%, about 10%, about 12%, about 14%, about 16%, about 18%, about20%, about 22%, about 24%, about 26%, about 28%, about 30%, about 32%,about 34%, about 36%, about 38%, about 40%, about 42%, about 44%, about46%, about 48%, about 50%, about 52%, about 54%, about 56%, about 58%,about 60%, about 62%, about 64%, about 66%, about 68%, about 70%, about72%, about 74%, about 76%, about 78%, about 80%, about 82%, about 84%,about 86%, about 88%, about 90%, about 92%, about 94%, about 96%, andabout 98% of the stoichiometric amount of polyamine curing agent ofFormula (1). In one embodiment, the epoxy resin composition contains thepolyamine curing agent of Formula (1) in a percentage selected from thegroup consisting of less than about 4% but greater than about 2%, lessthan about 6% but greater than about 2%, less than about 8% but greaterthan about 2%, less than about 10% but greater than about 2%, less thanabout 12% but greater than about 2%, less than about 14% but greaterthan about 2%, less than about 16% but greater than about 2%, less thanabout 18% but greater than about 2%, less than about 20% but greaterthan about 2%, less than about 22% but greater than about 2%, less thanabout 24% but greater than about 2%, less than about 26% but greaterthan about 2%, less than about 28% but greater than about 2%, less thanabout 30% but greater than about 2%, less than about 32% but greaterthan about 2%, less than about 34% but greater than about 2%, less thanabout 36% but greater than about 2%, less than about 38% but greaterthan about 2%, less than about 40% but greater than about 2%, less thanabout 42% but greater than about 2%, less than about 44% but greaterthan about 2%, less than about 46% but greater than about 2%, less thanabout 48% but greater than about 2%, less than about 50% but greaterthan about 2%, less than about 52% but greater than about 2%, less thanabout 54% but greater than about 2%, less than about 56% but greaterthan about 2%, less than about 58% but greater than about 2%, less thanabout 60% but greater than about 2%, less than about 62% but greaterthan about 2%, less than about 64% but greater than about 2%, less thanabout 66% but greater than about 2%, less than about 68% but greaterthan about 2%, less than about 70% but greater than about 2%, less thanabout 72% but greater than about 2%, less than about 74% but greaterthan about 2%, less than about 76% but greater than about 2%, less thanabout 78% but greater than about 2%, less than about 80% but greaterthan about 2%, less than about 82% but greater than about 2%, less thanabout 84% but greater than about 2%, less than about 86% but greaterthan about 2%, less than about 88% but greater than about 2%, less thanabout 90% but greater than about 2%, less than about 92% but greaterthan about 2%, less than about 94% but greater than about 2%, less thanabout 96% but greater than about 2%, and less than about 98% but greaterthan about 2% of the stoichiometric amount of polyamine curing agent ofFormula (1).

Unless otherwise stated herein the terms “hardener”, “curing agent”,“cross-linking agent” are used interchangeable as synonyms of“cross-linking agent”. As is the case with thermosetting epoxies, theprocessing properties (e.g. curing time, peak exotherm, mixed viscosity,etc.) and cured resin physical properties (Tg, tensile strength,flexibility modulus, chemical resistance, conductivity, adhesion, color,impact strength, etc.) can be modified by the addition of auxiliarymaterials to the base epoxy resin/hardener composition for the purposesof preparation of epoxy formulations tailored for a given application.Accordingly, in some embodiments, the epoxy resin composition furtherincludes an auxiliary material selected from the group consisting ofaccelerator, diluents, toughening agent, thickening agent, adhesionpromoter, optical brightener, pigment, adducting component, couplingagent, filler, decorative component, thixotropic agent, fluorophore,UV-absorber, anti-oxidant, monoamine, gloss additive and combinationsthereof.

In some embodiments, amino molecules that contain 2, or less than 2,active N—H hydrogens can be used in combination with the polyaminecuring agents of Formula (1). Primary monoamines, bis(secondary) diaminemolecules, and other molecules that contain only two active N—Hhydrogens are suitable for use in the epoxy resin composition of thepresent invention as chain extenders. In one embodiment, the chainextenders are used to adjust the cross-link density of a cured epoxyresin in accordance with exemplary embodiments of the present invention.By adding these chain extenders to the polyamine curing agents ofFormula (1) one can decrease the cross-linking density in the finalcured epoxy matrix. In an embodiment, specific, but non-limiting,examples of molecules that contain only two active N—H hydrogens includemonoethanolamine, 3-aminopropanol, 2-aminopropanol, benzylamine,aniline, p-anisidine, butylamine, piperazine, andN,N′-dimethylethylenediamine, tert-butylamine, and, sec-butylamine. Inan embodiment, the epoxy resin composition of the present inventionincludes at least one amine chain extender in an amount ranging fromabout 0% to about 98% relative to weight of the polyamine curing agentof Formula (1).

In some embodiments, conventional, non-labile polyamino molecules thatcontain greater than 2 N—H hydrogens are used in combination withpolyamine curing agents of Formula (1). Chain extenders can be combinedwith the polyamine curing agent of Formula (1) to increase the amount ofnondegradable cross-links in the final cured epoxy matrix. In oneembodiment, chain extenders in an amount of from about 5 wt. % to 25 wt.% is combined with the polyamine curing agent of Formula (1) to increasethe amount of nondegradable cross-links in the final cured epoxy matrix.In one embodiment, chain extenders in an amount selected from the groupconsisting of about 5 wt. % to about 25 wt. %, about 6 wt. % to about25, about 7 wt. % to about 25, about 8 wt. % to about 25 wt. %, about 9wt. % to about 25 wt. %, about 10 wt. % to about 25 wt. %, about 11 wt.% to about 25 wt. %, about 12 wt. % to about 25 wt. %, about 13 wt. % toabout 25 wt. %, about 14 wt. % to about 25 wt. %, about 15 wt. % toabout 25 wt. %, about 16 wt. % to about 25 wt. %, about 17 wt. % toabout 25 wt. %, about 18 wt. % to about 25 wt. %, about 19 wt. % toabout 25 wt. %, about 20 wt. % to about 25 wt. %, about 21 wt. % toabout 25 wt. %, about 22 wt. % to about 25 wt. %, about 23 wt. % toabout 25 wt. %, and about 24 wt. % to about 25 is combined with thepolyamine curing agent of Formula (1) to increase the amount ofnondegradable cross-links in the final cured epoxy matrix.

In some embodiments, the epoxy resin composition further includes areinforcing agent. In one embodiment, reinforcing agent is selected froma group consisting of glass fiber, carbon fiber, natural fiber, andchemical fiber, and the non-fibrous material is at least one selectedfrom a group consisting of carbon nanotube, carbon black, metalnanoparticle, organic nanoparticle, iron oxide, boron nitride, andcombinations thereof.

In another aspect, the present invention provides a method of curing anepoxy resin formulation in accordance with the present invention. In oneembodiment, the method comprises heating an epoxy resin composition ofthe present invention to form a cured epoxy resin composition. In oneembodiment, the epoxy resin composition is cured to a curing degree ofat least 25% cure. In one embodiment, the epoxy resin composition iscured to a curing degree of at least 35% cure. In one embodiment, theepoxy resin composition is cured to a curing degree of at least 45%cure. In one embodiment, the epoxy resin composition is cured to acuring degree of at least 55% cure. In one embodiment, the epoxy resincomposition is cured to a curing degree selected from the groupconsisting of at least 65% cure, at least 75% cure, at least 85% cure,and at least 95% cure.

In some embodiments, the method of curing an epoxy resin formulation inaccordance with the present invention is used to produce reinforcedcomposite. In one embodiment, the method of curing an epoxy resinformulation in accordance with the present invention produces acomposite reinforced with a reinforcing component selected from thegroup consisting of glass fibers, aramid fibers, graphite fibers, carbonfibers, natural fibers, non-natural fibers and combinations thereof.

In another aspect, the present invention provides a cross-linked polymermatrix, wherein the cross-linked polymer is derived from an epoxy resinhaving at least two epoxide and a cross-linking group derived from apolyamine curing agent represented by Formula (1):

wherein: each of R¹ and R² is independently selected from the groupconsisting of hydrogen, alkyl group, cycloalkyl group and aromaticgroup; or both of R¹ and R² forms a cyclic radical; each of R³, R⁴, R⁵and R⁶ is independently selected from the group consisting of hydrogen,alkyl group, cycloalkyl group and aromatic group; R³ and R⁴ can combinewith each other to form a cyclic radical; R⁵ and R⁶ can combine witheach other to form a cyclic radical; and each m and n is independentlyan integer ranging from 1 to 20. In one embodiment, cross-linked polymermatrix is derived from a diepoxide epoxy resin and a cross-linking groupderived from a polyamine curing agent represented by Formula (1). In oneembodiment, the cross-linked polymer matrix is reinforced with areinforcing agent derived from a reinforcing component selected from thegroup consisting of glass fibers, aramid fibers, graphite fibers, carbonfibers, natural fibers, non-natural fibers and combinations thereof. Inone embodiment, the cross-linked polymer matrix is a cross-linked epoxyresin, wherein the epoxy resin is selected from the group consisting ofglycidyl ether epoxy resin, glycidyl ester epoxy resin, glycidyl amineepoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, and phenolicepoxy resin. In one embodiment, the cross-linked polymer matrix isreinforced with the reinforcement material selected from the groupconsisting of a fibrous material and a non-fibrous material. In oneembodiment, the cross-linked polymer matrix is reinforced with a fibrousmaterial selected from a group consisting of glass fiber, carbon fiber,natural fiber, and chemical fiber. In one embodiment, the cross-linkedpolymer matrix is reinforced with a non-fibrous material selected fromthe group consisting of carbon nanotube, carbon black, metalnanoparticle, organic nanoparticle, iron oxide, and boron nitride. Inone embodiment, the reinforced cross-linked polymer matrix includes anauxiliary material selected from the group consisting of accelerator,diluents, toughening agent, thickening agent, adhesion promoter, opticalbrightener, pigment, adducting component, coupling agent, filler,decorative component, thixotropic agent, fluorophore, UV-absorber,anti-oxidant, monoamine, and gloss additive. In some embodiments, thereinforced cross-linked polymer matrix is prepared by at least onemethod selected from the group consisting of wet lay-up, vacuuminfusion, filament winding, and resin transfer molding, prepreg, andcompression molding.

In another aspect, the present invention provides a method for recyclinga cross-linked polymer matrix in accordance with the present invention.FIG. 4 shows a non-limiting example of the method for recycling across-linked polymer matrix in accordance with the present invention. Inone embodiment, the method for recycling the cross-linked polymer matrixcomprises degrading the cross-linked polymer matrix with an acid in thepresence of a solvent. In one embodiment, degrading the cross-linkedmatrix with an acid in the presence of a solvent is performed under aheating condition. In one embodiment, the cross-linked polymer matrix isdegraded with an acid selected from a group consisting of hydrochloricacid, acetic acid, lactic acid, formic acid, propionic acid, citricacid, methane sulfonic acid, p-toluene sulfonic acid, sulfuric acid,benzoic acid, and phthalic acid. In one embodiment, the cross-linkedpolymer matrix is degraded with an acid in the presence of a solventselected from the group consisting of methanol, ethanol, ethyleneglycol, isopropyl alcohol, butyl alcohol, pentanol, hexanol, heptanol,octanol alcohol, nonyl alcohol, water, and combinations thereof. In oneembodiment, the cross-linked polymer matrix is degraded with an acid inan amount ranging from about 2% to 90% by weight of the cross-linkedpolymer matrix. In one embodiment, the cross-linked polymer matrix isdegrated with an acid in an amount selected from about 2 wt. % to about90 wt. %, about 3 wt. % to about 90 wt. %, about 4 wt. % to about 90 wt.%, about 5 wt. % to about 90 wt. %, about 6 wt. % to about 90 wt. %,about 7 wt. % to about 90 wt. %, about 8 wt. % to about 90 wt. %, about9 wt. % to about 90 wt. %, about 10 wt. % to about 90 wt. %, about 11wt. % to about 90 wt. %, about 12 wt. % to about 90 wt. %, about 13 wt.% to about 90 wt. %, about 14 wt. % to about 90 wt. %, about 15 wt. % toabout 90 wt. %, about 16 wt. % to about 90 wt. %, about 17 wt. % toabout 90 wt. %, about 18 wt. % to about 90 wt. %, about 19 wt. % toabout 90 wt. %, about 20 wt. % to about 90 wt. %, about 21 wt. % toabout 90 wt. %, about 22 wt. % to about 90 wt. %, about 23 wt. % toabout 90 wt. %, about 24 wt. % to about 90 wt. %, about 25 wt. % toabout 90 wt. %, about 26 wt. % to about 90 wt. %, about 27 wt. % toabout 90 wt. %, about 28 wt. % to about 90 wt. %, about 29 wt. % toabout 90 wt. %, about 30 wt. % to about 90 wt. %, about 31 wt. % toabout 90 wt. %, about 32 wt. % to about 90 wt. %, about 33 wt. % toabout 90 wt. %, about 34 wt. % to about 90 wt. %, about 35 wt. % toabout 90 wt. %, about 36 wt. % to about 90 wt. %, about 37 wt. % toabout 90 wt. %, about 38 wt. % to about 90 wt. %, about 39 wt. % toabout 90 wt. %, about 40 wt. % to about 90 wt. %, about 41 wt. % toabout 90 wt. %, about 42 wt. % to about 90 wt. %, about 43 wt. % toabout 90 wt. %, about 44 wt. % to about 90 wt. %, about 45 wt. % toabout 90 wt. %, about 46 wt. % to about 90 wt. %, about 47 wt. % toabout 90 wt. %, about 48 wt. % to about 90 wt. %, about 49 wt. % toabout 90 wt. %, about 50 wt. % to about 90 wt. %, about 51 wt. % toabout 90 wt. %, about 52 wt. % to about 90 wt. %, about 53 wt. % toabout 90 wt. %, about 54 wt. % to about 90 wt. %, about 55 wt. % toabout 90 wt. %, about 56 wt. % to about 90 wt. %, about 57 wt. % toabout 90 wt. %, about 58 wt. % to about 90 wt. %, about 59 wt. % toabout 90 wt. %, about 60 wt. % to about 90 wt. %, about 61 wt. % toabout 90 wt. %, about 62 wt. % to about 90 wt. %, about 63 wt. % toabout 90 wt. %, about 64 wt. % to about 90 wt. %, about 65 wt. % toabout 90 wt. %, about 66 wt. % to about 90 wt. %, about 67 wt. % toabout 90 wt. %, about 68 wt. % to about 90 wt. %, about 69 wt. % toabout 90 wt. %, about 70 wt. % to about 90 wt. %, about 71 wt. % toabout 90 wt. %, about 72 wt. % to about 90 wt. %, about 73 wt. % toabout 90 wt. %, about 74 wt. % to about 90 wt. %, about 75 wt. % toabout 90 wt. %, about 76 wt. % to about 90 wt. %, about 77 wt. % toabout 90 wt. %, about 78 wt. % to about 90 wt. %, about 79 wt. % toabout 90 wt. %, about 80 wt. % to about 90 wt. %, about 81 wt. % toabout 90 wt. %, about 82 wt. % to about 90 wt. %, about 83 wt. % toabout 90 wt. %, about 84 wt. % to about 90 wt. %, about 85 wt. % toabout 90 wt. %, about 86 wt. % to about 90 wt. %, about 87 wt. % toabout 90 wt. %, about 88 wt. % to about 90 wt. %, and about 89 wt. % toabout 90 wt. % of the cross-linked polymer matrix.

In one embodiment, the cross-linked polymer matrix is degraded with anacid in an amount selected from the group consisting of about 2 wt. %,about 3 wt. %, about 4 wt. %, about 5 wt. %, about 6 wt. %, about 7 wt.%, about 8 wt. %, about 9 wt. %, about 10 wt. %, about 11 wt. %, about12 wt. %, about 13 wt. %, about 14 wt. %, about 15 wt. %, about 16 wt.%, about 17 wt. %, about 18 wt. %, about 19 wt. %, about 20 wt. %, about21 wt. %, about 22 wt. %, about 23 wt. %, about 24 wt. %, about 25 wt.%, about 26 wt. %, about 27 wt. %, about 28 wt. %, about 29 wt. %, about30 wt. %, about 31 wt. %, about 32 wt. %, about 33 wt. %, about 34 wt.%, about 35 wt. %, about 36 wt. %, about 37 wt. %, about 38 wt. %, about39 wt. %, about 40 wt. %, about 41 wt. %, about 42 wt. %, about 43 wt.%, about 44 wt. %, about 45 wt. %, about 46 wt. %, about 47 wt. %, about48 wt. %, about 49 wt. %, about 50 wt. %, about 51 wt. %, about 52 wt %,about 53 wt. %, about 54 wt. %, about 55 wt. %, about 56 wt. %, about 57wt. %, about 58 wt. %, about 59 wt. %, about 60 wt. %, about 61 wt. %,about 62 wt. %, about 63 wt. %, about 64 wt. %, about 65 wt. %, about 66wt. %, about 67 wt. %, about 68 wt. %, about 69 wt. %, about 70 wt. %,about 71 wt. %, about 72 wt. %, about 73 wt. %, about 74 wt. %, about 75wt. %, about 76 wt. %, about 77 wt. %, about 78 wt. %, about 79 wt. %,about 80 wt. %, about 81 wt. %, about 82 wt. %, about 83 wt. %, about 84wt. %, about 85 wt. %, about 86 wt. %, about 87 wt. %, about 88 wt. %,about 89 wt. %, and about 90 wt. %.

In some embodiments, the method for recycling a cross-linked polymermatrix in accordance with the present invention is carried out under aheating condition. In one embodiment, the cross-linked polymer matrix isdegraded at a temperature ranging from 15° C. to 400° C. In oneembodiment, the cross-linked polymer matrix is degraded at a temperatureranging from 60° C. to 120° C. In one embodiment, the cross-linkedpolymer matrix is degraded at a temperature selected from the groupconsisting of about 60° C. to about 120° C., about 61° C. to about 120°C., about 62° C. to about 120° C., about 63° C. to about 120° C., about64° C. to about 120° C., about 65° C. to about 120° C., about 66° C. toabout 120° C., about 67° C. to about 120° C., about 68° C. to about 120°C., about 69° C. to about 120° C., about 70° C. to about 120° C., about71° C. to about 120° C., about 72° C. to about 120° C., about 73° C. toabout 120° C., about 74° C. to about 120° C., about 75° C. to about 120°C., about 76° C. to about 120° C., about 77° C. to about 120° C., about78° C. to about 120° C., about 79° C. to about 120° C., about 80° C. toabout 120° C., about 81° C. to about 120° C., about 82° C. to about 120°C., about 83° C. to about 120° C., about 84° C. to about 120° C., about85° C. to about 120° C., about 86° C. to about 120° C., about 87° C. toabout 120° C., about 88° C. to about 120° C., about 89° C. to about 120°C., about 90° C. to about 120° C., about 91° C. to about 120° C., about92° C. to about 120° C., about 93° C. to about 120° C., about 94° C. toabout 120° C., about 95° C. to about 120° C., about 96° C. to about 120°C., about 97° C. to about 120° C., about 98° C. to about 120° C., about99° C. to about 120° C., about 100° C. to about 120° C., about 101° C.to about 120° C., about 102° C. to about 120° C., about 103° C. to about120° C., about 104° C. to about 120° C., about 105° C. to about 120° C.,about 106° C. to about 120° C., about 107° C. to about 120° C., about108° C. to about 120° C., about 109° C. to about 120° C., about 110° C.to about 120° C., about 111° C. to about 120° C., about 112° C. to about120° C., about 113° C. to about 120° C., about 114° C. to about 120° C.,about 115° C. to about 120° C., about 116° C. to about 120° C., about117° C. to about 120° C., about 118° C. to about 120° C., and about 119°C. to about 120° C.

In one embodiment, the cross-linked polymer matrix is degraded at atemperature selected from the group consisting of about 60° C., about61° C., about 62° C., about 63° C., about 64° C., about 65° C., about66° C., about 67° C., about 68° C., about 69° C., about 70° C., about71° C., about 72° C., about 73° C., about 74° C., about 75° C., about76° C., about 77° C., about 78° C., about 79° C., about 80° C., about81° C., about 82° C., about 83° C., about 84° C., about 85° C., about86° C., about 87° C., about 88° C., about 89° C., about 90° C., about91° C., about 92° C., about 93° C., about 94° C., about 95° C., about96° C., about 97° C., about 98° C., about 99° C., about 100° C., about101° C., about 102° C., about 103° C., about 104° C., about 105° C.,about 106° C., about 107° C., about 108° C., about 109° C., about 110°C., about 111° C., about 112° C., about 113° C., about 114° C., about115° C., about 116° C., about 117° C., about 118° C., about 119° C., andabout 120° C.

In some embodiments, the cross-linked polymer matrix is degraded at atemperature ranging from 20° C. to 400° C. In one embodiment, thecross-linked polymer matrix is degraded at a temperature selected fromthe group consisting of about 20° C. to about 400° C., about 25° C. toabout 400° C., about 30° C. to about 400° C., about 35° C. to about 400°C., about 40° C. to about 400° C., about 45° C. to about 400° C., about50° C. to about 400° C., about 55° C. to about 400° C., about 60° C. toabout 400° C., about 65° C. to about 400° C., about 70° C. to about 400°C., about 75° C. to about 400° C., about 80° C. to about 400° C., about85° C. to about 400° C., about 90° C. to about 400° C., about 95° C. toabout 400° C., about 100° C. to about 400° C., about 105° C. to about400° C., about 110° C. to about 400° C., about 115° C. to about 400° C.,about 120° C. to about 400° C., about 125° C. to about 400° C., about130° C. to about 400° C., about 135° C. to about 400° C., about 140° C.to about 400° C., about 145° C. to about 400° C., about 150° C. to about400° C., about 155° C. to about 400° C., about 160° C. to about 400° C.,about 165° C. to about 400° C., about 170° C. to about 400° C., about175° C. to about 400° C., about 180° C. to about 400° C., about 185° C.to about 400° C., about 190° C. to about 400° C., about 195° C. to about400° C., about 200° C. to about 400° C., about 205° C. to about 400° C.,about 210° C. to about 400° C., about 215° C. to about 400° C., about220° C. to about 400° C., about 225° C. to about 400° C., about 230° C.to about 400° C., about 235° C. to about 400° C., about 240° C. to about400° C., about 245° C. to about 400° C., about 250° C. to about 400° C.,about 255° C. to about 400° C., about 260° C. to about 400° C., about265° C. to about 400° C., about 270° C. to about 400° C., about 275° C.to about 400° C., about 280° C. to about 400° C., about 285° C. to about400° C., about 290° C. to about 400° C., about 295° C. to about 400° C.,about 300° C. to about 400° C., about 305° C. to about 400° C., about310° C. to about 400° C., about 315° C. to about 400° C., about 320° C.to about 400° C., about 325° C. to about 400° C., about 330° C. to about400° C., about 335° C. to about 400° C., about 340° C. to about 400° C.,about 345° C. to about 400° C., about 350° C. to about 400° C., about355° C. to about 400° C., about 360° C. to about 400° C., about 365° C.to about 400° C., about 370° C. to about 400° C., about 375° C. to about400° C., about 380° C. to about 400° C., about 385° C. to about 400° C.,about 390° C. to about 400° C., and about 395° C. to about 400° C.

In some embodiments, the cross-linked polymer matrix is degraded at atemperature selected from the group consisting of about 20° C., about25° C., about 30° C., about 35° C., about 40° C., about 45° C., about50° C., about 55° C., about 60° C., about 65° C., about 70° C., about75° C., about 80° C., about 85° C., about 90° C., about 95° C., about100° C., about 105° C., about 110° C., about 115° C., about 120° C.,about 125° C., about 130° C., about 135° C., about 140° C., about 145°C., about 150° C., about 155° C., about 160° C., about 165° C., about170° C., about 175° C., about 180° C., about 185° C., about 190° C.,about 195° C., about 200° C., about 205° C., about 210° C., about 215°C., about 220° C., about 225° C., about 230° C., about 235° C., about240° C., about 245° C., about 250° C., about 255° C., about 260° C.,about 265° C., about 270° C., about 275° C., about 280° C., about 285°C., about 290° C., about 295° C., about 300° C., about 305° C., about310° C., about 315° C., about 320° C., about 325° C., about 330° C.,about 335° C., about 340° C., about 345° C., about 350° C., about 355°C., about 360° C., about 365° C., about 370° C., about 375° C., about380° C., about 385° C., about 390° C., about 395° C., and about 400° C.

In some embodiments, the cross-linked polymer matrix is degraded byheating the cross-linked polymer matrix with an acid at a temperatureselected from the group consisting of less than about 400° C. butgreater than about 10° C., less than about 395° C. but greater thanabout 10° C., less than about 390° C. but greater than about 10° C.,less than about 385° C. but greater than about 10° C., less than about380° C. but greater than about 10° C., less than about 375° C. butgreater than about 10° C., less than about 370° C. but greater thanabout 10° C., less than about 365° C. but greater than about 10° C.,less than about 360° C. but greater than about 10° C., less than about355° C. but greater than about 10° C., less than about 350° C. butgreater than about 10° C., less than about 345° C. but greater thanabout 10° C., less than about 340° C. but greater than about 10° C.,less than about 335° C. but greater than about 10° C., less than about330° C. but greater than about 10° C., less than about 325° C. butgreater than about 10° C., less than about 320° C. but greater thanabout 10° C., less than about 315° C. but greater than about 10° C.,less than about 32° C. but greater than about 10° C., less than about305° C. but greater than about 10° C., less than about 300° C. butgreater than about 10° C., less than about 295° C. but greater thanabout 10° C., less than about 290° C. but greater than about 10° C.,less than about 285° C. but greater than about 10° C., less than about280° C. but greater than about 10° C., less than about 275° C. butgreater than about 10° C., less than about 270° C. but greater thanabout 10° C., less than about 265° C. but greater than about 10° C.,less than about 260° C. but greater than about 10° C., less than about255° C. but greater than about 10° C., less than about 250° C. butgreater than about 10° C., less than about 245° C. but greater thanabout 10° C., less than about 240° C. but greater than about 10° C.,less than about 235° C. but greater than about 10° C., less than about230° C. but greater than about 10° C., less than about 225° C. butgreater than about 10° C., less than about 220° C. but greater thanabout 10° C., less than about 215° C. but greater than about 10° C.,less than about 22° C. but greater than about 10° C., less than about205° C. but greater than about 10° C., less than about 200° C. butgreater than about 10° C., less than about 195° C. but greater thanabout 10° C., less than about 190° C. but greater than about 10° C.,less than about 185° C. but greater than about 10° C., less than about180° C. but greater than about 10° C., less than about 175° C. butgreater than about 10° C., less than about 170° C. but greater thanabout 10° C., less than about 165° C. but greater than about 10° C.,less than about 160° C. but greater than about 10° C., less than about155° C. but greater than about 10° C., less than about 150° C. butgreater than about 10° C., less than about 145° C. but greater thanabout 10° C., less than about 140° C. but greater than about 10° C.,less than about 135° C. but greater than about 10° C., less than about130° C. but greater than about 10° C., less than about 125° C. butgreater than about 10° C., less than about 120° C. but greater thanabout 10° C., less than about 115° C. but greater than about 10° C.,less than about 12° C. but greater than about 10° C., less than about105° C. but greater than about 10° C., less than about 100° C. butgreater than about 10° C., less than about 95° C. but greater than about10° C., less than about 90° C. but greater than about 10° C., less thanabout 85° C. but greater than about 10° C., less than about 80° C. butgreater than about 10° C., less than about 75° C. but greater than about10° C., less than about 70° C. but greater than about 10° C., less thanabout 65° C. but greater than about 10° C., less than about 60° C. butgreater than about 10° C., less than about 55° C. but greater than about10° C., less than about 50° C. but greater than about 10° C., less thanabout 45° C. but greater than about 10° C., less than about 40° C. butgreater than about 10° C., less than about 35° C. but greater than about10° C., less than about 30° C. but greater than about 10° C., less thanabout 25° C. but greater than about 10° C., less than about 20° C. butgreater than about 10° C., and less than about 15° C. but greater thanabout 10° C.

In some embodiments, the cross-linked polymer matrix is degraded byheating the cross-linked polymer matrix with an acid for a time of fromabout 1 hour to about 48 hours. In some embodiments, the cross-linkedpolymer matrix is degraded by heating the cross-linked polymer matrixwith an acid for a time of from about 1 hour to 12 hours.

In some embodiments, the cross-linked polymer matrix is degraded byheating the cross-linked polymer matrix with an acid for a time selectedfrom the group consisting of about 1 hour to about 48 hours, about 2hours to about 48 hours, about 3 hours to about 48 hours, about 4 hoursto about 48 hours, about 5 hours to about 48 hours, about 6 hours toabout 48 hours, about 7 hours to about 48 hours, about 8 hours to about48 hours, about 9 hours to about 48 hours, about 10 hours to about 48hours, about 11 hours to about 48 hours, about 12 hours to about 48hours, about 13 hours to about 48 hours, about 14 hours to about 48hours, about 15 hours to about 48 hours, about 16 hours to about 48hours, about 17 hours to about 48 hours, about 18 hours to about 48hours, about 19 hours to about 48 hours, about 20 hours to about 48hours, about 21 hours to about 48 hours, about 22 hours to about 48hours, about 23 hours to about 48 hours, about 24 hours to about 48hours, about 25 hours to about 48 hours, about 26 hours to about 48hours, about 27 hours to about 48 hours, about 28 hours to about 48hours, about 29 hours to about 48 hours, about 30 hours to about 48hours, about 31 hours to about 48 hours, about 32 hours to about 48hours, about 33 hours to about 48 hours, about 34 hours to about 48hours, about 35 hours to about 48 hours, about 36 hours to about 48hours, about 37 hours to about 48 hours, about 38 hours to about 48hours, about 39 hours to about 48 hours, about 40 hours to about 48hours, about 41 hours to about 48 hours, about 42 hours to about 48hours, about 43 hours to about 48 hours, about 44 hours to about 48hours, about 45 hours to about 48 hours, about 46 hours to about 48hours, and about 47 hours to about 48 hours.

In some embodiments, the cross-linked polymer matrix is degraded byheating the cross-linked polymer matrix with an acid for a time selectedfrom the group consisting of less than about 48 hours but greater thanabout 1 hour, less than about 47 hours but greater than about 1 hour,less than about 46 hours but greater than about 1 hour, less than about45 hours but greater than about 1 hour, less than about 44 hours butgreater than about 1 hour, less than about 43 hours but greater thanabout 1 hour, less than about 42 hours but greater than about 1 hour,less than about 41 hours but greater than about 1 hour, less than about40 hours but greater than about 1 hour, less than about 39 hours butgreater than about 1 hour, less than about 38 hours but greater thanabout 1 hour, less than about 37 hours but greater than about 1 hour,less than about 36 hours but greater than about 1 hour, less than about35 hours but greater than about 1 hour, less than about 34 hours butgreater than about 1 hour, less than about 33 hours but greater thanabout 1 hour, less than about 32 hours but greater than about 1 hour,less than about 31 hours but greater than about 1 hour, less than about30 hours but greater than about 1 hour, less than about 29 hours butgreater than about 1 hour, less than about 28 hours but greater thanabout 1 hour, less than about 27 hours but greater than about 1 hour,less than about 26 hours but greater than about 1 hour, less than about25 hours but greater than about 1 hour, less than about 24 hours butgreater than about 1 hour, less than about 23 hours but greater thanabout 1 hour, less than about 22 hours but greater than about 1 hour,less than about 21 hours but greater than about 1 hour, less than about20 hours but greater than about 1 hour, less than about 19 hours butgreater than about 1 hour, less than about 18 hours but greater thanabout 1 hour, less than about 17 hours but greater than about 1 hour,less than about 16 hours but greater than about 1 hour, less than about15 hours but greater than about 1 hour, less than about 14 hours butgreater than about 1 hour, less than about 13 hours but greater thanabout 1 hour, less than about 12 hours but greater than about 1 hour,less than about 11 hours but greater than about 1 hour, less than about10 hours but greater than about 1 hour, less than about 9 hours butgreater than about 1 hour, less than about 8 hours but greater thanabout 1 hour, less than about 7 hours but greater than about 1 hour,less than about 6 hours but greater than about 1 hour, less than about 5hours but greater than about 1 hour, less than about 4 hours but greaterthan about 1 hour, less than about 3 hours but greater than about 1hour, and less than about 2 hours but greater than about 1 hour.

In some embodiments, the cross-linked polymer matrix is degraded byheating the cross-linked polymer matrix with an acid for a time selectedfrom the group consisting of 1 hour, about 2 hours, about 3 hours, about4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours,about 9 hours, about 10 hours, about 11 hours, about 12 hours, about 13hours, about 14 hours, about 15 hours, about 16 hours, about 17 hours,about 18 hours, about 19 hours, about 20 hours, about 21 hours, about 22hours, about 23 hours, about 24 hours, about 25 hours, about 26 hours,about 27 hours, about 28 hours, about 29 hours, about 30 hours, about 31hours, about 32 hours, about 33 hours, about 34 hours, about 35 hours,about 36 hours, about 37 hours, about 38 hours, about 39 hours, about 40hours, about 41 hours, about 42 hours, about 43 hours, about 44 hours,about 45 hours, about 46 hours, about 47 hours, and about 48 hours.

In some embodiments, the cross-linked polymer matrix is degraded byheating the cross-linked polymer matrix with an acid for a time selectedfrom the group consisting of less than about 48 hours but greater thanabout 1 hour, less than about 47 hours but greater than about 2 hours,less than about 46 hours but greater than about 3 hours, less than about45 hours but greater than about 4 hours, less than about 44 hours butgreater than about 5 hours, less than about 43 hours but greater thanabout 6 hours, less than about 42 hours but greater than about 7 hours,less than about 41 hours but greater than about 8 hours, less than about40 hours but greater than about 9 hours, less than about 39 hours butgreater than about 10 hours, less than about 38 hours but greater thanabout 11 hours, less than about 37 hours but greater than about 12hours, less than about 36 hours but greater than about 13 hours, lessthan about 35 hours but greater than about 14 hours, less than about 34hours but greater than about 15 hours, less than about 33 hours butgreater than about 16 hours, less than about 32 hours but greater thanabout 17 hours, less than about 31 hours but greater than about 18hours, less than about 30 hours but greater than about 19 hours, lessthan about 29 hours but greater than about 20 hours, less than about 28hours but greater than about 21 hours, less than about 27 hours butgreater than about 22 hours, less than about 26 hours but greater thanabout 23 hours, and less than about 25 hours but greater than about 24hours.

In some embodiments, the method for recycling a cross-linked polymermatrix includes the step of recovering a degradation product of thecross-linked polymer matrix via a filtration process and/or aprecipitation process.

In general, the diamino compounds of Formula (1) can be used as monomersand/or cross-linkers to make polymeric materials such as nylons,epoxies, polyurethanes, acrylamides or other type polymers orcross-linked polymers and/or materials. The diamino compounds of Formula(1) can also be used as monomers or cross-linkers for the preparation ofdesigner materials that can further be imbued with the ability todegrade under acidic conditions. Polymer degradation can be accomplishedwith these materials because, inter alia, the incorporated acetal andketal linkages are susceptible to cleavage by various chemical means.For example, the acetal and ketal linkages can be cleaved by hydrolysisunder acidic conditions. Thus, use of the present diaminoacetals anddiaminoketals of Formula (1) as monomers produce polymeric structurethat can be predictably degraded into smaller molecular fragments underacidic conditions.

Similarly, use of the present diaminoacetals and diaminoketals ofFormula (1) as cross-linkers produce polymeric materials that can becleaved into smaller molecular fragments by cleaving the aminoacetal andaminoketals of the cross-links, for example, under acidic conditions.The rate of acid hydrolysis of acetal and ketals linkages can be used tofine-tune the physical properties of the polymeric materials. Ingeneral, the rate of acid hydrolysis decreases in the order ofketal>acetal>formal. Thus, polymeric materials that contain theseacid-labile linkages can be useful in designing more environmentallysustainable materials that can degraded at will via chemical means.

In some embodiments, the epoxy resin composition disclosed herein can beused as an adhesive composition. In some embodiments, the epoxycomposition disclosed herein can be used as a coating composition. Insome embodiments, the epoxy composition disclosed herein can be used asan encapsulation material.

Conventional diamine compounds that feed the plastics industry areproduced at high volume—often at the thousands of tons per annum scale.In order for diaminoacetals to find use in cost driven industries likethe plastic industry, an economical strategy for their synthesis is aprerequisite. The present invention discloses such a strategy as thestarting materials and/or precursors used in the present invention canbe derived from inexpensive and readily available feedstocks.Furthermore, in the present invention, a process capable of convertingthe precursors into the diamino products is disclosed, and should have ahigh potential for translation into an optimized industrial process.Given various shortcomings of the known processes for makingdiaminoacetals in the prior art, the present disclosure encompassedherein now provides a strategy for the preparation of diaminoacetalswith advantageous results over the methods previously known in the art.The over-all process of this invention includes two steps. In the firststep, dicyanoacetals are directly prepared by the reaction of a compoundcontaining both an alcohol group and a cyano group (now, herein referredto a cyanohydrin) with an aldehyde or ketone, (or an aldehyde or ketoneequivalent). In the second step the dicyanoacetal is hydrogenated togive the corresponding diaminoacetal. A strategy which employscyanohydrins as starting materials, as disclosed in this invention, forthe production of diaminoacetals is particularly attractive becausecyanohydrins can generally derived from their reaction of hydrogencyanide (or its salts) with aldehydes, ketones, or ethylene oxide, allof with are high-volume industrial chemicals. The preparation of adicyanoacetal and the subsequent reduction to the correspondingdiaminoacetal has not been documented in the prior art.

II. Examples Step I: Preparation of a Dicyanoacetal of Type Formula (2)

In an embodiment, the first step in the synthesis of Formula (1) is thepreparation of Formula (2). Compounds of the type Formula (2) may resultfrom the condensation of 2 molar equivalents of a cyanohydrin, with 1molar equivalent of an aldehyde and/or ketone or an aldehyde- and/orketone equivalent. Certain compounds of Formula (2) can be prepared fromthe reaction of a cyanohydrin with a ketone or ketone equivalent (aketone equivalent is sometimes referred to as a “masked ketone”).Certain compounds of Formula (2) can be prepared from the reaction of acyanohydrin with an aldehyde or aldehyde equivalent (an aldehydeequivalent is sometimes referred to as a “masked aldehyde”). It is knowin the art that the formation of an acetal from an aldehyde/ketone andan alcohol is an equilibrium process and the position of the equilibriumis influenced by both the choice of starting alcohol and thealdehyde/ketone used. It is also known in the art that removal ofwater—in the case of aldehyde/ketone starting materials—or methanol (orother alcohol)—in the cased of a masked aldehyde/or ketone such asdimethoxypropane—will serve to increase the yield of acetal product. Itis also known in the art that an acid can be used to catalyze theformation of acetals. However, many of the dicyanoacetals represented byFormula (2) have hitherto not been subject to synthesis in the art, andtherefore represent novel compounds.

In some embodiments, the reactions to obtain polycyano compound ofFormula (2) compounds, the exact molar ratio of cyanohydrin toaldehyde/ketone used can vary, but one of ordinary skill in the art canselect the ratio that balances the yield of the polycyano compound ofFormula (2) versus parameters such as the starting materials costs andthe ability to recycle any excess starting materials or reagents. Ingeneral, it is preferable to use a molar ratio of cyanohydrin toaldehyde/ketone in a ratio of from about 4:1 to 1:1, respectively. Insome embodiments, it is preferable to use a molar ratio of cyanohydrinto aldehyde/ketone of about 1:1 respectively. In some embodiments, it ismost preferable to use a molar ratio of cyanohydrin to aldehyde/ketoneof from about 2:4 to about 2:1, respectively. In some embodiments, it ismost preferable to use a molar ratio of cyanohydrin to aldehyde/ketoneof from about 2:1 to about 1;1, respectively. Specific, butnon-limiting, examples of cyanohydrins are ethylene cyanohydrin(Sigma-Aldrich, Saint Louis, Mo., USA), glycolonitrile (see OrganicSyntheses, Coll. Vol. 3, p. 436 (1955); Vol. 27, p. 41 (1947).),lactonitrile (Sigma-Aldrich, Saint Louis, Mo., USA), and mandelonitrile(see Organic Syntheses, Coll. Vol. 1, p. 336 (1941); Vol. 6, p. 58(1926).). Specific, but non-limiting, examples of ketones and aldehydesare acetone, methyl ethyl ketone, cyclohexanone, cyclopentanone,acetaldehyde, benzaldehyde, butyraldehyde, formaldehyde, andisobutyraldehyde. Specific, but non-limiting, examples of ketone- andaldehyde equivalents are 2,2-dimethoxypropane, acetaldehyde dimethylacetal, paraformaldehyde, and trioxane. In general, the condensation ofa cyanohydrin with an aldehyde/ketone according to the present inventionmay be facilitated by the use of an acidic catalyst.

A great deal of flexibility exists with respect to the type of acidcatalyst that can be used to prepare the dicyanoacetals anddicyanoaketals. The acid catalyst may be organic, inorganic, homogenous,heterogeneous or on a solid-support. Specific, but non-limiting,examples of acid catalyst that are suitable for the preparation ofcertain dicyanoacetals of type Formula (2) are acetic acid, Amberlyst®resins, acidic zeolites, HCl, H₂SO₄, p-toluenesulfonic acid, or otheracid. In general, the yield of dicyanoacetals is greatly facilitated bythe removal of formed water from the reaction mixture. This can beaccomplished, for example, via azeotropic distillation with a Dean Starkapparatus, or with the use of an auxiliary dehydration reagent. Somespecific, but non-limiting, examples of dehydration agents include,calcium chloride, calcium sulfate, magnesium sulfate, molecular sieves,and sodium sulfate. In general, when compared to distillation methods,the removal of water via the use of an auxiliary dehydration agent wouldadd increased reagent expense to the production of a Formula (2)compound; however, many dehydration reagents can be regenerated andreused. The use of a dehydration agent may have certain advantages overdistillation methods, as it can allow the preparation of Formula (2)compounds at room temperature or below, which may be advantageous withcertain combinations of cyanohydrins and aldehyde/ketones. In the caseof masked aldehydes/ketones such as acetaldehyde dimethylacetal ordimethoxypropane, methanol, as opposed to water, is formed during thecourse of dicyanoacetal formation. In such cases, it is generallyadvantageous to remove the formed methanol, for example, via azeotropicdistillation, with a Dean-Stark apparatus or with an auxiliary materialthat can absorb methanol such as molecular sieves. Overall, for theformation of polycyanoacetals represented by Formula (2), a great dealof flexibility exists with regard to acid catalysts, water (or alcohol)removal conditions, temperature, and ratio of reagents/startingmaterials; for a given polycyano compound of Formula (2), optimalsynthetic conditions can be easily determined by routing experimentationby one skilled in the art.

Step II: Hydrogenation of a Dicyanoacetal/Ketal to a Diaminoacetal/Ketal

The chemical synthesis of the polyamino acetal/ketal in accordance withthe present invention can be generically represented by the syntheticscheme of FIG. 2 below.

In an embodiment, the transformation is carried out via a catalytichydrogenation reaction. In an embodiment, the conversion of Formula (2)to Formula (1) may be effected in the liquid or vapor phase employing asuitable active hydrogenation catalyst. In an embodiment, conventionalhydrogenation catalysts that are known in the art to effect theconversion of nitrile moieties into amines can be used. Specific, butnon-limiting, examples of which may include as the active component anoble metal from the group Ru, Rh, Pd, and Pt, or a transition metal thegroup Cu, Cr, Co, Ni, Fe, including, but not limited to, Raney® typecatalysts, Sponge Metal® type catalysts and chromite catalyst. In anembodiment, bimetallic catalysts of one or more transition metals and/ornoble metals may also be used. In an embodiment the catalyst may be on asolid support. One skilled in the art, when viewing the presentdisclosure, will understand how to select a catalyst, includingconsiderations of the useful life of any particular catalyst and cost.In an embodiment, an example of a preferred catalyst is a Raney® Ni or aSponge® Ni. In an embodiment, the hydrogenation can be conducted in theliquid or vapor phase at temperatures ranging between 10° C. and 200° C.and at hydrogen pressures of 70 psi to about 5000 psi, and in anotherembodiment, in the temperate range between 20° C. and 150° C. and underpressures between 100 psi to about 2000 psi. In an embodiment, theconversion of Formula (2) to Formula (1) may be enhanced by the presenceof ammonia during the reaction, preferably in the range, from 1 mole to60 moles of ammonia per mole of Formula (2) used. In an embodiment,hydrogenation of Formula (2) may be carried out using anhydrous ammonia.In an embodiment, hydrogenation is carried out in aqueous ammonia. In anembodiment, an optional cosolvent(s) may be used such as, but notlimited to, for example, methanol, ethanol, dioxane, and tetrahydrofuranor any solvent that is not substantially hydrogenated during thereaction or decomposed by the added ammonia. Upon the completion of thereaction, the catalyst can be removed via filtration and Formula (1) canbe obtained after removal of any solvents. In an embodiment, thecatalyst can be recycled. In an embodiment, the conversion ofdicyanoacetals to diaminoacetals can be carried out via a batch process,using a type of batch reactor. In an embodiment, the conversion ofdicyanoacetals to diaminoacetals can be carried out via continuousprocess, for example, by using a type of continuous reactor. In anembodiment, any excess reagent and/or solvents can be recycled. In anembodiment, Formula (2) can be further purified via distillation underreduced pressure.

The examples set forth below are intended to be illustrative and not tobe construed as limiting in scope of the invention disclosed herein inany way.

Example 1 Preparation of Dicyano Acetal C-1

To a 1 L glass bottle was charged ethylene cyanohydrin (78 g),benzaldehyde (29 g), 300 mL of dichloromethane, concentrated HCl (1.1 g)and calcium sulfate (300 g). The mixture was allowed to stand at roomtemperature overnight, and then filtered to remove the solids. Thefiltrate was washed with 300 mL of a 5% NaOH solution, and 300 mL ofwater, and then solvent removed via rotary evaporation. The resultingcrude material was further purified by heating (50-100° C.) under highvacuum (0.7 mmHg) for 2 hours, to give 37 g of dicyano acetal C-1.

Example 2 Preparation of Dicyano Acetal C-2

To a 10 L glass reactor equipped with internal cooling coils was chargedethylene cyanohydrin (711 g), 1 L of dichloromethane, and 3 A MolecularSieves (600 g). The reactor was cooled to 4° C. and thenisobutyraldehyde (280 g) was added in one portion. Then Amberlyst®-15(36 g) was added in one portion, and the cooling maintained at 4-5° C.After 22 hr, an additional portion of isobutyraldehyde (50 g) was addedto the reaction, and the reaction allowed to continue over night. In thefollowing day, the reactor contents where filtered and the resultantliquid layer was washed with a 2% aqueous NaOH solution (2×5 L) and thenconcentrated on a rotary evaporator. The resulting crude oilcrystallized upon standing, after which time the supernatant wasdecanted, leaving behind 470 g of dicyano acetal C-2 as crystals: ¹H NMR(CDCl₃, 300 MHz): 0.95 (d, 6H), 1.92 (m, 1H), 2.62 (t, 4H), 3.68-3.76(m, 2H), 3.79-3.86 (m, 2H), 4.23 (d, 1H).

Example 3 Preparation of Dicyano Ketal C-3

A solution comprised of ethylene cyanohydrin (426.5 g), dimethoxypropane(260.4 g), acetic acid (10 g) and methyl tert-butyl ether (1 L), wascirculated through a stainless steel column (2″ diameter; 5′ tall)packed with 5 A molecular sieves (2 Kg). After 2 hrs of circulation, thecolumn was drained and further washed with an additional 0.5 L methyltort-butyl ether. The combined contents were concentrated via rotaryevaporation. The resulting oil crystallized upon standing in a coldbath, and residual liquid impurities discarded. 410 g of dicyano ketalC-3 was obtained as crystals: ¹H NMR (CDCl₃, 400 MHz): 1.41 (s, 6H),2.59 (t, 4H), 2.72 (t, 4H).

Example 4 Preparation of Dicyano Acetal C-4

To a 1 L jacketed glass reactor was charged ethylene cyanohydrin (150g), 1 L of dichloromethane, and 3 A Molecular Sieves (300 g). Thereactor was cooled to 3° C. and then Amberlyst®-15 (10 g) was added inone portion. Acetaldehyde (90 g) was then added portion wise over a 20min period, and the reaction allowed to progress overnight while coolingwas maintained at 3-5° C. The solids where filtered off in thesubsequent day, and triethylamine (5 g) was added to the liquidfiltrate. The organic layer was washed with water, concentrated on arotary evaporator, and the resultant crude oil further purified viaflash distillation to yield 120 g of dicyano acetal C-4 as an oil: ¹HNMR (CDCl₃, 400 MHz): 1.36 (d, J=5.2 Hz, 3H), 2.62 (t, J=6 Hz, 4H),3.69-3.74 (m, 2H), 3.80-3.85 (m, 2H), 4.86 (q, J=5.2 Hz, 1H).

Example 5a Preparation of Dicyano Acetal C-5

To a 1 L three-neck Round Bottom Flask equipped with a mechanicalstirrer and a Dean Stark apparatus was charged ethylene cyanohydrin (142g), paraformaldehyde (30 g), p-toluenesulfonic acid (3 g) and 300 mL ofcyclohexane. The mixture was then heated to reflux with vigorousstirring. After 2.5 hours, 19 mL of water evolved in the Dean-Starktrap, and the heating was stopped. The organic layer was washed withaqueous NaOH, water, and brine, and then concentrated on a rotaryevaporator to yield the crude oil. Dicyano acetal C-5 was obtained afterpurification via fractional vacuum distillation.

Example 5b Preparation of Dicyano Acetal C-5

To a 10 L glass reactor was charged ethylene cyanohydrin (426 g),paraformaldehyde (90 g), dichloromethane (1.2 L), and magnesium sulfate(21 g). The reactor was cooled to an internal temperature of −10° C. andthen sulfuric acid (28 g) was added drop-wise via an addition funnelover a 1 hr period, with mechanical stirring. The reaction was continuedfor 1 hr, and then the contents decanted from the sludge, washed with 3%bicarbonate solution, separated, and the organic layer concentrated togive 245 g of dicyano acetal C-5 as an oil.

Example 6 Preparation of Dicyano Acetal C-6

In a 500 mL jacketed reactor, was charged glycolonitrile (20 g),dichloromethane (150 mL), magnesium sulfate (21 g), and acetaldehyde (8g). The reactor was cooled until the internal temperature reached −14°C. Then, sulfuric acid (28 g) was added drop-wise over a 5 min period,while the reaction contents were agitated with a mechanical stirrer. Theaddition of sulfuric acid caused a rise in internal temperature to 2° C.Once internal temperature reached −10° C., external cooling was stopped,and the reaction contents decanted. The resultant organic layer waswashed with a saturated bicarbonate solution, water, and brine. Theorganic layer was dried over potassium carbonate and then concentratedon a rotary evaporator to give dicyano acetal C-6 as an oil: ¹H NMR(CDCl₃, 400 MHz) 1.47 (d, 3H), 4.29 (d, J=16 Hz, 1H), 4.35 (d, J=16 Hz,1H), 5.04 (q, 1H).

Example 7 Preparation of Dicyano Acetal C-7

In a 500 mL jacketed reactor, was charged lactonitrile (50 g),dichloromethane (300 mL), magnesium sulfate (42 g), and acetaldehyde (16g). The reactor was cooled until the internal temperature reached −14°C. Then, sulfuric acid (28 g) was added drop-wise over a ˜1 hr period,while the reaction contents were agitated with a mechanical stirrer.After the addition of sulfuric acid was complete, the reaction wasstirred for an additional 30 minutes, and then the reactor contentsdecanted. The resultant organic layer was washed with a saturatedbicarbonate solution, water, and brine. The organic layer was dried overpotassium carbonate and then concentrated on a rotary evaporator to give30 g of dicyano acetal C-7 as an oil.

Example 8 Preparation of Diamino Acetal C-8

To a high pressure stainless steel reactor was charged dicyano acetalC-2 of example 2 (140 g), 700 mL of tetrahydrofuran, 700 mL of aqueousNH₃, and 30 g of Raney® Ni (type 2400). The reactor was then chargedwith hydrogen to 650 psi and the reactor contents were stirredvigorously at room temperature. The reaction progress was monitored bythe pressure drop. After the reaction was judged to be complete, thecatalyst was removed by filtering the reactor contents through a pad ofCelite®. The filtrate was concentrated on a rotary evaporator and thecrude product purified via fractional distillation under reducedpressure (1.3 mmHg) to give 110 g of diamino acetal C-8 as an oil: ¹HNMR (CDCl₃, 300 MHz) 0.90 (d, J=6.9 Hz, 6H), 1.71 (pentet, 4H),1.82-1.93 (m, 1H), 2.80 (t, 4H), 3.45-3.52 (m, 2H), 3.64-3.71 (m, 2H),4.07 (d, J=6.6 Hz, 1H).

Example 9 Preparation of Diamino Acetal C-9

To a high pressure stainless steel reactor was charged dicyano acetalC-4 of example 4 (120 g), 600 mL of methanol, 600 mL of aqueous NH₃, and24 g of Raney® Ni (type 2400). The reactor was then charged withhydrogen to 1000 psi. The reactor contents were stirred vigorously atroom temperature, and then the reaction progress was monitored by thepressure drop. After the reaction was judged to be complete, thecatalyst was removed by filtering the reactor contents through a pad ofCelite®. The filtrate was concentrated on a rotary evaporator and thecrude product purified via flash vacuum distillation to give 75 g ofdiamino acetal C-9. Further purification of the product was realized viafractional distillation under reduced pressure (bp=87° C.; 0.3 mmHg) togive an oil with low color.

Example 10 Preparation of Dicyano Ketal C-10

To a high pressure stainless steel reactor was charged dicyano ketal C-3of example 3 (170 g), 540 g of methanol, 500 g of aqueous NH₃, and 30 gof Raney® Ni (type 2400). The reactor was then charged with hydrogen to1000 psi. The reactor contents were stirred vigorously at roomtemperature and reaction progress was monitored by the pressure drop.After the reaction was judged to be complete, the catalyst was removedby filtering the reactor contents through a pad of Celite®. The filtratewas concentrated on a rotary evaporator and the crude product firstpurified via flash vacuum distillation, and then further purified viafractional distillation under reduced pressure to give 145 g of diaminoketal C-10 (bp=87° C.; 0.3 mmHg) as an oil with low color: ¹H NMR(CDCl₃, 400 MHz) 1.33 (s, 6H), 1.41 (bs, 4H), 1.68 (pentet, 4H), 2.78(t, 4H), 3.47 (t, 4H).

Example 11 Preparation of Diamino Acetal C-11

To a high pressure stainless steel reactor was charged dicyano acetalC-6 of example 6 (5.7 g), 100 ml of methanol, 100 ml of aqueous NH₃, and10 g of Raney® Ni (type 2400). The reactor was then charged withhydrogen to 1000 psi. The reactor contents were stirred vigorously atroom temperature. After the reaction was judged to be complete, thecatalyst was removed by filtering the reactor contents through a pad ofCelite®. The filtrate was concentrated on a rotary evaporator and thecrude product purified via flash vacuum distillation to give the titlediaminoacetal (2.5 g) as an oil: ¹H NMR (CDCl₃, 300 MHz) 1.32 (d, J=5.4Hz, 3H), 1.48 (bs, 4H), 2.86 (t, 4H), 3.42-3.48 (m, 2H), 3.59-3.66 (m,2H), 4.73 (q, 1H).

Example 12 Preparation of Diamino Acetal C-12

To a high pressure stainless steel reactor was charged dicyanocetal C-7of example 7 (2.7 g), 50 ml of methanol, 50 ml of aqueous NH₃, and 3 gof Raney® Ni (type 2400). The reactor was then charged with hydrogen to1000 psi. The reactor contents were stirred vigorously at roomtemperature. After the reaction was judged to be complete, the catalystwas removed via filtration. The filtrate was concentrated on a rotaryevaporator and the crude product purified via flash vacuum distillationto give diamino acetal C-12 (1 g) as an oil: obtained as a mixture ofdiastereomers; ¹H NMR (CDCl₃, 300 MHz) 1.11 (d, J=6.3 Hz), 1.17 (d,J=6.3 Jz), 1.18 (d, J=6.3 Hz), 1.32 (d, J=5.1 Hz), 1.33 (d, J=5.1 Hz),1.41 (bs, 4H), 2.62-2.74 (m, 4H), 3.55-3.75 (m, 2H), 4.75-4.79 (m, 1H).

Example 13 Preparation of Diamino Acetal C-13

To a high pressure stainless steel reactor was charged dicyanoacetal C-5of example 5 (9 g), 200 mL of methanol, 200 mL of aqueous NH₃, and 10 gof Raney® Ni (type 2400). The reactor was then charged with hydrogen to1000 psi and the reactor contents were stirred vigorously at roomtemperature. After the reaction was judged to be complete, the catalystwas removed by filtration. The filtrate was concentrated on a rotaryevaporator and the crude product purified via flash distillation underreduced pressure to give 7 g (bp=80-90 @ 0.3 mmHg) of the titlediaminoacetal as an oil: ¹H NMR (CDCl₃, 400 MHz) 1.32 (bs, 4H), 1.72(pentet, 4H), 2.80 (t, J=6.8 Hz, 4H), 3.60 (t, J_(av)=6.2 Hz, 4H), 4.62(s, 2H).

Example 14 Preparation of Diamino Acetal C-14

To a high pressure stainless steel reactor was charged dicyanoacetal C-5of example 5 (20 g), 200 mL of methanol, 200 mL of aqueous NH₃, and 10 gof Sponge Nickel (type A-4000). The reactor was then charged withhydrogen to 1000 psi and the reactor contents were stirred vigorously atroom temperature. After the reaction was judged to be complete, thecatalyst was removed by filtration. The filtrate was concentrated on arotary evaporator and the crude product further purified via flashdistillation under reduced pressure to give title diamino acetal C-14 asan oil. The compound was further purified via fractional vacuumdistillation (bp=73-74 @ 0.17 mmHg).

Example 15

The addition of conventionally used polyamine hardeners in the art ofepoxy has been found to have a deleterious effect on the recycling,removal, or dissolving the epoxy compositions according to the presentinvention. The incorporation of only 2% chemical equivalents of theconventionally used “non-degradable” polyamines can begin to inhibit thefull dissolution of the epoxy compositions, and about 20% chemicalequivalents is about enough to prevent the matrix from dissolving underthe acidic conditions detailed in the is invention. For example, a curedepoxy composition consisting of a bisphenol A-type epoxy resin (EEW=188)and a compound type of formula (1) diamine (AEW=40.5), and the diamineunder the trade name EDR-148 (AEW=37) gave the following results thefollowing Table 1:

TABLE 1 Parts Parts Cleavable Parts equivalence of Wt % dissolved ResinHardener EDR-148 DER-148 Epoxy 200 44 0   0% >99% 200 43 1 2.5% >95% 20042 2   5% ~30% 200 40 4  10% ~15% 200 36 8  20% None

However, when conventionally used polyamine hardeners are combined withthe acid-labile polyamine curing agent of Formula (1), properties ofepoxy resin compositions, containing both acid degradable andnon-degradable cross-links, can be tuned on the basis of the relativeproportions of the polyamines used.

III. Alternative Processes

In one embodiment, the present invention provides a process chemicalsynthesis for the preparation of di-(2-aminoethyl) formal acetal offormula I. In one embodiment, the process comprises reacting a compoundof formula Va with a second compound selected from the group consistingof ammonia, ammonium salt, and combinations or equivalents (such asammonium hydroxide) thereof, to form di-(2-aminoethyl) formal acetal offormula I:

wherein L¹ and L² are the same or different and each is independently aleaving group or leaving group precursor. In one embodiment, each of L¹and L² is independently selected from the group consisting halogen or analkyl- or aryl-sulfonyloxy group. In one embodiment, each of L¹ and L²is independently selected from the group consisting of a chloro, abromo, an iodo, a mesyloxy, a besyloxy and a tosyloxy group. In oneembodiment, each of L¹ and L² is independently selected from the groupconsisting of a halide, methanesulfonate, para-toluenesulfonate,trifluoromethane sulfonate, mono nitro and dinitro phenolate.

In some embodiments, the process chemical synthesis for the preparationof di-(2-aminoethyl) formal acetal of formula I further comprises addingan additive to the reaction. In one embodiment, the additive is aniodide salt. In one embodiment, the iodide salt is a potassium iodide ora sodium iodide or a combination of both.

In some embodiments, the process chemical synthesis for the preparationof di-(2-aminoethyl) formal acetal of formula I, the reaction isconducted at a temperature range of from about 0° C. to 200° C. In oneembodiment, the reaction is conducted at a temperature range of fromabout 40° C. to 140° C. In one embodiment, the reaction is optionallyconducted in the presence of a solvent. In one embodiment, the solventis selected from the group consisting of water, methanol, ethanol,dioxane and combinations thereof.

In some embodiments, the process chemical synthesis for the preparationof di-(2-aminoethyl) acetal of formula I, the reaction is conducted in apressurized system. In one embodiment, the reaction is conducted in thepresence of excess ammonia or ammonia equivalents. In one embodiment,the molar proportion of the ammonia or ammonia equivalents to thecompound of formula Va is about 20:1. In one embodiment, the molarproportion of the ammonia or said ammonia equivalents to the compound offormula Va is greater than about 20:1. In one embodiment, the molarproportion of the ammonia or the ammonia equivalents to the compound offormula Va is less than about 20:1.

In some embodiments, the process of chemical synthesis for thepreparation of di-(2-aminoethyl) formal acetal of formula I comprisesreducing di-(2-nitroethyl) formal acetal Vb with a reducing agent toform the compound formula I:

In one embodiment, the reducing agent is hydrogen gas in the presence ofa catalyst. In one embodiment, the reducing agent is selected from thegroup consisting of hydrogen in the presence of catalytic Raney nickel,hydrogen in the presence of catalytic Palladium on carbon (Pd/C),catalytic Pd/C and ammonium formate in methanol, hydrogen in thepresence of catalytic PtO₂, iron metal in the presence of acid, and ironmetal/FeCl₃ in the presence of acid. In one embodiment, thehydrogenation catalyst is recovered and recycled. In one embodiment, thehydrogenation catalyst is recovered via filtration after the reaction iscomplete. In one embodiment, the reaction is conducted at a temperaturerange of from about 20° C. to 200° C. In one embodiment, the reaction isconducted at a temperature range of from about 40° C. to 140° C. In oneembodiment, the reaction is conducted under hydrogen gas pressure offrom about 1 atm to about 1000 atm.

In some embodiments, the process of chemical synthesis for thepreparation of di-(2-aminoethyl) formal acetal of formula I comprisesreacting ethanolamine with paraformaldehyde or any suitably maskedformaldehyde equivalent in the presence of an acid to formdi-(2-aminoethyl) formal acetal salt of formula VIII; and reacting saiddi-(2-aminoethyl) formal acetal salt VII with a base to formdi-(2-aminoethyl) formal acetal I:

In one embodiment, the acid is an inorganic acid. In one embodiment, theacid is selected from the group consisting of HCl, HBr and H₂SO₄. In oneembodiment, the acid is an organic acid. In one embodiment, the organicacid is p-toluenesulfonic acid, acetic acid or methanesulfonic acid. Inone embodiment, the suitably masked formaldehyde equivalent is trioxane.In one embodiment, the ratio of a molar equivalence of the acid toethanolamine is greater than 1. In one embodiment, the ethanolamine ispretreated with an acid prior to the reaction with the paraformaldehydeor the any suitably masked formaldehyde equivalent. In one embodiment,the process further comprises the step of adding a drying agent to thereaction mixture. In one embodiment, the drying agent is anhydrousmagnesium sulfate (MgSO₄). In one embodiment, the drying agent isanhydrous sodium sulfate (Na₂SO₄) or anhydrous potassium sulfate(K₂SO₄). In one embodiment, the process is conducted under Dean-Starktype reaction condition to remove any water formed during the reaction.In one embodiment, the process is conducted at temperature ranging fromabout 0° C. to about 220° C.

In some embodiments, the process of chemical synthesis for thepreparation of di-(2-aminoethyl) formal acetal of formula I comprisesreacting ethanolamine with a formylacetal of formula VIII to formdi-(2-aminoethyl) formal acetal salt of formula VII; and reacting thedi-(2-aminoethyl) formal VIII alt of formula VII with a base VIIdi-(2-aminoethyl) formal acetal of formula I:

In some embodiments, the present invention provides a process ofchemical synthesis for the preparation of di-(3-aminopropyl) formalacetal of formula X. In one embodiment, the process comprises acatalytic hydrogenation reaction of a compound of formula IX:

Epoxies are an important class of thermosetting polymers. Epoxy resinsare typically hardened or cured by a cross-linking reaction using one ofthree general methods. The chemistry of epoxy curing is explained ingreat detail in the Handbook of Composites (edited by S. T. Peters,Chapter 3, pp 48-74, published by Chapman & Hall, 1998). The propertiesand applications of cured resin are greatly influenced by the choice ofthe hardener formulation or the method of curing.

One method is simply the reaction of the epoxy resin with itself (i.e.homopolymerization) via a ring-opening polymerization mechanism of theepoxy groups. The self-curing of epoxy resins usually requires anelevated temperature but can be initiated with either a Lewis acid- or aLewis base catalyst (as opposed to a curing agent).

In the second method, the epoxy resin is cured with a cyclic acidanhydride. The anhydride can react with the epoxy group, pendanthydroxyls, or residual water to form a carboxylate intermediate, whichthen reacts with the epoxy group, causing a self-perpetuating reactionbetween the anhydride and the epoxy resin. Catalytic amounts of tertiaryamines are commonly used as additives as they facilitate the opening ofthe anhydride. Typically, anhydride epoxy formulations generally do notreadily cure at room temperature, and are generally cured at elevatedtemperatures.

In the third method, the epoxy resin reacts with polyvalent nucleophilessuch as polyamines to form a polymeric network of essentially infinitemolecular weight. Epoxy groups will react with potentially every aminecontaining an active hydrogen atom, so that a simple diamine (NH2—R—NH2)acts as a tetra-functional cross-linker, reacting with four epoxygroups. The ring opening of the epoxy ring with a primary or secondaryamine generates a stable C—N bond, and the reaction is essentiallyirreversible. Aliphatic polyamines are widely used in ambienttemperature curing compositions. Aromatic amines are generally lessreactive than aliphatic amines, so they are primarily used in elevatedtemperature curing compositions. The use of aromatic diamine hardenerssuch as 4,4′-methylenedianiline (MDA) or 4,4′-diaminodiphenyl sulfone(DDS) are commonly used in epoxy applications that require enhancedtemperature properties such as high glass transition temperature (Tg) orin composite manufacturing techniques that require long pot-life atambient temperature such as a pre-impregnated (“prepreg”) method,wherein, for example, composite fibers may already have a material suchas an epoxy present.

Epoxies serve massive global markets in adhesives and coatings, and arealso one of the industry standard thermosetting plastic matrices usedfor construction of fiber reinforced plastic (FRP). FRPs are compositematerials consisting of a polymer matrix and a fiber such as carbonfiber, fiberglass, aramid fiber, natural fiber, or other fiber. Thefiber serves to enhance the properties of the plastic in areas such asstrength and elasticity. FRPs are also commonly referred to as “plasticcomposites” or, for simplicity, just “composites.” The term “plasticcomposites” can also embody plastic materials that have non-fibrousentities incorporated in them such as metals or nanomaterials. Plasticcomposites provide lightweight alternatives to other structuralmaterials (e.g., steel or aluminum) and are widely used in theautomotive, aerospace, nautical craft, wind energy, and sporting goodssectors. The incorporation of lightweight composites can offersubstantial environmental benefits by way of leading to increased energyefficiency; yet, the positive impact of thermosetting plastic compositesis offset by their lack of recyclability and persistence in theenvironment. The predicted waste accumulation in the growing wind powerindustry is an illustrious example. The current output of wind energy isapproximately 10 times that of the production in 1980, and windmillblade propellers can reach over 60 meters in length. The materialwastage from wind motor blade production is estimated to reach 225,000tons per year by 2034. The weight percentage of epoxy in fiberreinforced epoxies typically is in the range of 25-40%. The rawmaterials (i.e. the plastic and fiber) that go into compositeconstruction can be expensive, and are usually of petrochemical origins.Thus, there are both economic and environmental drivers for thedevelopment of new reworkable epoxy thermosetting compositions thatwould enable the manufacture of recyclable fiber reinforced epoxycomposites.

Of the three general epoxy curing methods describe above, epoxycompositions based on diepoxides (“resin”) and polyamines (“hardener”)to form a cross-linked polymeric network of essentially infinitemolecular weight are very common (the combination of “resin+hardener” issometimes referred to as “cured epoxy” or “cured resin” or simply“resin” or epoxy). The widespread utility of such epoxy formulations forcomposite manufacturing and other structural applications is due totheir generally excellent processablity prior to curing and theirexcellent post-cure adhesion, mechanical strength, thermal profile,chemical resistance, etc. Further, the high-density, three-dimensionalnetwork of epoxies makes epoxies robust materials, tolerant of a widerange of environmental conditions. At the same time, the cross-linkednetwork makes the removal, recycling, and/or reworkability of epoxy, orepoxy-based materials, notoriously difficult. The cross-linkingreactions that occur with conventionally used polyamine epoxiesformulation are essentially irreversible; therefore, the material cannotbe re-melted and re-shaped without decomposition; the material cannot bereadily dissolved either. As a result, fiber reinforced epoxies orepoxy-based composite materials are not amenable to standard recyclingpractices because the epoxy matrix and fibers cannot be readilyseparated, and recovered. Thermosetting composites are typicallydisposed of in landfills, or by burning. An emerging technology fordisposal of carbon fiber composites involves special incinerators burnaway the plastic matrix of the composite, leaving behind the carbonfiber, which then can be reclaimed. However, the value of the thermosetmatrix is not extracted in a repurposable from as it is destroyed in theincineration process.

The intractability of a cured epoxy resin stems, primarily, from itshighly cross-linked network. Those in the art can understand that if thelinks in the three-dimensional network can be cleaved under controlledconditions, then the network can be disassembled into smaller, solublemolecules and/or polymers, and therefore the cured matrix canpotentially be separated and recovered from the fiber in a composite. Byproviding for the manufacture of recyclable epoxy composites, componentsof the plastic matrix and components of the reinforcement material canbe recovered by way of a recycling step. In principal, such type ofrecyclable epoxy compositions can be accomplished through use of eithera dissolvable (or degradable) resin or a curing agent that contains abond capable of cleavage under a specific set of conditions. Themajority of the prior art on cleavable epoxy compositions has beenfocused on incorporation of different cleavable groups in the resincomponent. Such reports are also geared toward the use of epoxy as areworkable adhesive for electronics applications that allow glued orencapsulated components to be debonded under a specific set ofconditions. Selected examples of such reworkable epoxy compositionsinclude U.S. Pat. Nos. 5,932,682, 5,560,934, and 5,512,613, eachreferring to a reworkable epoxy thermosetting composition based on adiepoxide component in which the moiety connecting the two epoxy groupsis an acid labile acyclic ketal or acetal linkage. The cured resins areshown to be useful for adhesives and for electronic encapsulates for useas removable electronic encapsulation. The anhydride-cured resins areshown to disassemble in acidic environments.

U.S. Pat. No. 6,887,737 B1 refers to a reworkable epoxy thermosettingcomposition based on a resin component that contains at least twocleavable acetal or thioacetal linkages. The described epoxycompositions are thermally reworkable.

U.S. Pat. No. 6,657,031 B1 describes thermally reworkable epoxycompositions for use in electronic underfills based on a diepoxidecomponent that contains thermally labile ester linkages, allowing bondedelectronic components to more easily be detached after heating.

As disclosed herein for the first time, a reworkable epoxy compositionthat is designed to have cleavable linkages in the hardener components,as opposed to the resin component, is more attractive on bothperformance and economic grounds. The skilled artisan will understandthat hardener components of epoxy compositions are often interchanged.The skilled artisan will understand that the volume percentage of ahardener is significantly less than that of the resin component incommonly used epoxy compositions (i.e. any added cost is more diluted).The skilled artisan will understand that the industrial standard epoxyresin used for structural and composite applications is the diglycidylether of bisphenol A (DGEBPA) of various grades. As will be illustratedby the disclosure encompassed herein, the breaking of cross-links inreworkable epoxy compositions derived from amino curing agents withcleavable linkages and diepoxide resins can lead to the formation oflinear polymers. The present disclosure thereby provides a mechanism forthe transformation of a thermosetting matrix into a thermoplastic, whichis a recyclable material. As disclosed herein, the molecular structureof the cleavable linkage in the hardener is paramount to the degradationability of the thermoset matrix in the ambient environment, and just thesame, the ease or difficulty of the reworkability or recycling of thecured epoxy compositions. Ideally, degradation would not occur in thematerials' ambient environment, but only when recycling is selectivelydesirable.

International Patent Application No. PCT/CN2011/076980 discloses the useof acid liable amine hardeners for reworkable epoxy compositions.Specifically, the use of aminoacetal, aminoketal, aminoorthoester, oraminoorthocarbonate hardeners with epoxy resins is described. Whenimmersed in acidic environments, the cross-links that make up thethree-dimensional network of the cured epoxy, breakdown, and thecured-epoxy can be dissolved. The ease or difficulty of epoxydissolution can be controlled by the type of hardener employed.International Patent Application No. PCT/CN2012/075084 discloses the useof acid liable amine hardeners for reworkable epoxy compositionscontaining one or more reinforcing components. When immersed in acidicenvironments, the cross-links that make up the three-dimensional networkof the cured, reinforced epoxy break down. The cured-epoxy can bedissolved and the reinforcing components recovered. The ease ordifficulty of epoxy dissolution can be controlled by the type ofhardener employed.

Existing thermosetting composite recycling technology entails theincineration of the plastic constitution of the material and recoverythe reinforcement fiber. In an embodiment as encompassed herein, the useof reworkable epoxy compositions to fabricate composites provides a morefully recyclable approach because it enables both plastic and fibers tobe recovered from the composite. In an embodiment, the cross-linkedepoxy resin degrades into epoxy-based polymers or smaller molecularfragments, which may be thermoformable and have useful properties. Aswill be understood by the skilled artisan, epoxy thermoplastics areengineered polymers that can be used in other industrial applications.The polymer obtained from recycling may be reused or repurposed in otherapplications that are well suited for thermoplastics such as powdercoatings, laminates, injection molding, compression molding, etc.

In an embodiment, the combined mass recovery of the reinforcementmaterials and epoxy degradation material can exceed 80%, and thereinforcement material can be recovered in good form provided that it issufficiently stable to the basic recycling conditions. In an embodiment,the recycling methods of the reworkable epoxy resin compositions andproducts/composite materials encompassed herein are relatively mild,economical, and easy to control. For example, the processes can besimple enough to be performed at the site of product manufacturing,whereby prost-production epoxy scrap waste could be recycled instead ofbeing thrown in the landfill.

The economic implications of the disclosed reworkable epoxy compositionsfor composite product manufactures are potentially substantial, as itallows value to be extracted back from expenditures and manufacturingcosts. Thus, the present disclosure meets a primary objective behindrecycling—in addition to environmental protection—in that itdemonstrates the breakdown of end-of-life products in to their rawmaterial and/or high value material that can be reused to make newproducts. It also fulfills the long-term goals of the cradle-to-cradlelife cycle in that it helps promote recycling as a prime alternativesource to raw materials.

This disclosure relates, in part, to processes for the preparation ofpolyaminoacetals, including the compound of formula (I), also known asdi-(2-aminoethyl) formal acetal:

In an embodiment, encompassed herein are processes for the preparationdi-(2-aminoethyl) formal (Formula I).

Formula I contains an acetal group, specifically a formal group, whichlinks two primary amine end groups. Because Formula I contains twoprimary amine groups, it can be used to make polymeric materials (e.g.,nylons) or cross-linked polymers such as epoxies or polyurethanes, byway of several non-limiting examples. Polymeric materials derived fromFormula I may be degradable under acidic conditions by way of the acetallinkage, which is acidic labile. Degradable polymeric materials may havea variety of applications. A synthetic process for the preparation ofdi-(2-aminoethyl) formal that is both economical and amenable tomulti-ton scale synthesis could enable the cost-effective manufacture ofdegradable materials. Encompassed herein are multiple differentsynthetic routes that may be used for the preparation ofdi-(2-aminoethyl) formal.

In an embodiment, a direct and economical route for the preparation ofFormula I is a single-step sequence involving the direct reaction ofethanolamine with formaldehyde. However, this process does not lead tothe formation of I, but instead leads to the production of a1,3,5-triazine (Formula II) as show in scheme 1.

The production of Formula II can easily be rationalized by the fact thatthe more reactive amino group of ethanolamine reacts with formaldehyde,instead of the less reactive hydroxyl group. Suitably protectedethanolamine derivatives, such as, but not limited to,N-(2-hydroxyethyl)phthalimide, can be used in place of ethanolamine toprovide Formula I in a two step sequence as is shown in scheme 2. Thisgeneral approach is the most used method for the preparation of FormulaI in the prior art as is documented, for example, in U.S. Pat. No.5,191,015. The reported overall yield for this sequence is generally inthe range of 50-60%. While this documented procedure is relativelystraightforward to perform in the laboratory setting, the process is notideal for a multi-ton industrial process. The method is not atomeconomical as nearly 5 ton of the N-(2-hydroxyethyl)phthalimide (III)starting material would be required for the production of every 1 ton ofFormula I.

U.S. Pat. No. 2,409,675 is the other documented process for thepreparation of di-(2-aminoethyl) formal of Formula I in the prior art.The patent discloses preparation of Formula I via a multi-step methodthat generally entails: 1) the reaction of glyconitrile with excess ofan acetal; 2) hydrogenation of the resulting unsymmetrical cyanoacetalin the presence of ammonia and a hydrogenation catalyst; 3) treatment ofthe unsymmetrical cyanoacetal with excess of acid, which promotes adisproportiaonation reaction and leads to the salt of di-(2-aminoethyl)formal; and 4) isolation of I after deprotonation with a base. U.S. Pat.No. 2,409,675 discloses a multi-step chemical synthesis ofdi-(2-aminoethyl) formal acetal (I) according to the following Scheme 3:

The invention is further described by the following examples. It shouldbe recognized that variations based on the inventive features are withinthe skill of the ordinary artisan, and that the scope of the inventionshould not be limited by the examples. To properly determine the scopeof the invention, an interested party should consider the claims herein,and any equivalent thereof. In addition, all citations herein areincorporated by reference, and unless otherwise expressly stated, allpercentages are by weight.

In another embodiment, encompassed herein are processes for thepreparation di-(3-aminopropyl) formal (Formula X).

Formula X contains an acetal group, specifically a formal group, whichlinks two primary amine end groups. Because Formula X contains twoprimary amine groups, it can be used to make polymeric materials (e.g.,nylons) or cross-linked polymers such as epoxies or polyurethanes, byway of a few non-limiting examples. Polymeric materials derived fromFormula X may be engendered with the property of degradability underacidic conditions because the said compound contains an acetal linkage,which is acidic labile. Degradable polymeric materials may have avariety of applications. A synthetic process for the preparation ofdi-(3-aminopropyl) formal that is both economical and amenable tomulti-ton scale synthesis could enable the cost-effective manufacture ofdegradable materials. In an embodiment, the disclosure encompassedherein describes several different synthetic routes that may be used forthe preparation of di-(3-aminopropyl) formal.

Given various shortcomings of the known processes for makingdi-(2-aminoethyl) formal acetal, a need exists for economical andscalable synthetic processes for the preparation of di-(2-aminoethyl)formal acetal and related compounds. As described herein, the disclosureencompassed herein now provides multiple processes for the preparationof the molecules described herein, with advantageous results over themethods previously known in the art.

In an aspect the present invention provides a set of processes ofchemical synthesis that may be used for the preparation ofpolyaminoacetals. In an embodiment, a process of chemical synthesis ofdi-(2-aminoethyl) formal acetal I is described. In one embodiment, saidprocess comprises reacting a compound of formula Va with a secondcompound selected from the group consisting of ammonia, ammonium salt,and combinations or equivalents (such as ammonium hydroxide) thereof, toform a compound formula I, wherein L¹ and L² are the same or differentand each is independently a leaving group or leaving group precursor.

In an embodiment, each of L¹ and L² is independently selected from thegroup consisting halogen or an alkyl- or aryl-sulfonyloxy group. In anembodiment, each of L¹ and L² is independently selected from the groupconsisting of a chloro, a bromo, an iodo, a mesyloxy, a besyloxy and atosyloxy group. In another embodiment, each of L¹ and L² isindependently selected from the group consisting of a halide,methanesulfonate, para-toluenesulfonate, trifluoromethane sulfonate,mono nitro and dinitro phenolate.

In some embodiments, said process of chemical synthesis ofdi-(2-aminoethyl) formal acetal I further comprises adding an additiveto the reaction. In one embodiment, said additive is an iodide salt. Ina further embodiment, said iodide salt is a potassium iodide or a sodiumiodide or a combination of both.

In an embodiment, the substitution reaction is conducted at atemperature range of from about 0° C. to 200° C. In an embodiment, thesubstitution reaction is conducted at a temperature range of from about40° C. to 140° C. In another embodiment, the substitution reaction isoptionally conducted in the presence of a solvent. In anotherembodiment, the substitution reaction is optionally conducted in thepresence a solvent is selected from the group consisting of, but notlimited to, water, methanol, ethanol, dioxane and combinations thereof.In an embodiment, the substitution reaction is conducted in apressurized system, at a pressure selected based on the desired reactionproperties and results. In an embodiment, the substitution reaction isconducted in the presence of excess ammonia or ammonia equivalents. Inone embodiment, the molar proportion of ammonia or ammonia equivalent tothe compound of formula (5) is about 20:1. In another embodiment, themolar proportion of ammonia or ammonia equivalent to the compound offormula Va is greater than about 20:1. In another embodiment, the molarproportion of ammonia or ammonia equivalent to the compound of formulaVa is less than about 20:1.

In an embodiment, I is isolated by distillation of the reaction mixture.In another embodiment, I is isolated by extracting the reaction mixturewith a solvent followed by evaporation of the solvent and/ordistillation of the extract.

In some exemplary embodiments of a process of chemical synthesis ofdi-(2-aminoethyl) formal acetal I, the process comprises reducingdi-(2-nitroethyl) formal acetal Vb with a reducing agent to form thecompound formula I as shown in scheme 5 below:

In an embodiment, the reducing agent is hydrogen gas in the presence ofa catalyst. In one embodiment, reducing agent is selected from the groupconsisting of hydrogen in the presence of catalytic Raney nickel,hydrogen in the presence of catalytic Palladium on carbon (Pd/C),catalytic Pd/C and ammonium formate in methanol, hydrogen in thepresence of catalytic PtO₂, iron metal in the presence of acid, and ironmetal/FeCl₃ in the presence of acid.

In another embodiment, the hydrogenation catalyst is recovered andrecycled. In another embodiment, the hydrogenation is recovered viafiltration after the reaction is complete. In an embodiment, thereaction is conducted at a temperature range of from about 20° C. to200° C. In an embodiment, the reaction is conducted at a temperaturerange of from about 40° C. to 140° C. As will be understood based on thedisclosure set forth herein, the selected temperature may vary dependingupon the catalyst used, etc. . . . In an embodiment, I is isolated bydistillation of the reaction mixture. In another embodiment, I isisolated by extracting the reaction mixture with a solvent followed byevaporation of the solvent and/or distillation of the extract. Inanother embodiment, I is isolated by filtration of the reaction mixturefollowed by distillation of the filtrate.

In some embodiments, the reaction is conducted under hydrogen gaspressure of from about 1 atm to about 1000 atm.

In some exemplary embodiments of a process of chemical synthesis ofdi-(2-aminoethyl) formal acetal I, said process comprising reactingethanolamine with paraformaldehyde or any suitably masked formaldehydeequivalent in the presence of an acid to form di-(2-aminoethyl) formalacetal salt VII; and reacting said di-(2-aminoethyl) formal acetal saltVII with a base to form di-(2-aminoethyl) formal acetal I as shown inscheme 6 below.

In one embodiment, said acid is an inorganic acid. In anotherembodiment, said acid is selected from the group consisting of HCl, HBrand H₂SO₄. In an embodiment, said acid is an organic acid. In anotherembodiment, said organic acid is p-toluenesulfonic acid, acetic acid, ormethanesulfonic acid.

In one embodiment, the suitably masked formaldehyde equivalent istrioxane. In another embodiment, the ratio of the molar equivalence ofthe acid to ethanolamine is greater than 1. In some embodiments,ethanolamine is pretreated with an acid prior to the reaction with theparaformaldehyde or the any suitably masked formaldehyde equivalent.

In some embodiments, the process of chemical synthesis of scheme 6further comprises an adding a drying agent to the reaction mixture. Inone embodiment, said drying agent is anhydrous magnesium sulfate(MgSO₄). In another embodiment, said drying agent is sodium sulfate(Na₂SO₄) or potassium sulfate (K₂SO₄). In some embodiments, the processof chemical synthesis of scheme 6 is conducted under Dean-Stark typereaction condition to remove any water formed during the reaction. Insome embodiments, the process of chemical synthesis of scheme 6 isconducted at temperature ranging from about 0° C. to about 220° C.

In some exemplary embodiments, a process of chemical synthesis of thepresent invention comprises reacting ethanolamine with a formylacetalVIII to form di-(2-aminoethyl) formal acetal salt VII; and reacting saiddi-(2-aminoethyl) formal acetal salt VII with a base to formdi-(2-aminoethyl) formal acetal I as shown in scheme 7 below.

Example 1 Preparation of I Via the Ammonolysis of di-(2-chloroethyl)Formal (Formula V)

The key embodiment of this example is the formation of Formula I via theammonolysis of di-(chloroethyl) formal (Formula V).

The synthesis of Formula V can be readily achieved from the reaction of2-chloroethanol and formaldehyde (which can be employed in solid form asparaformaldehyde or trioxane), which are relatively inexpensive rawmaterials. There are well established processes for the preparation ofFormula V, which are suitable for large scale preparation. The keyreaction of this example is the alkylation reaction between 2equivalents of ammonia and Formula V to form Formula I. In anembodiment, this reaction can be carried out according to standardreaction protocols that involve the reaction of an alkyl chloride withammonia or ammonia equivalent like ammonium hydroxide. In an embodiment,the reaction is amenable to being carried out in a pressure vessel in abatch process, or in a continuous reactor in a continuous process. In anembodiment, Formula I can be prepared by the reaction ofdi-(2-chloroethyl) formal Formula V with an excess of anhydrous liquidNH₃ in an autoclave reactor or under pressurized conditions, such as ina pressure vessel. NH₃ should be used in excess to minimize the amountof multiple alkylation byproducts. In the case of a dialkyl chloridelike Formula V, multiple alkylation would lead to the formation ofoligomers (or even crosslinking). While the complete avoidance of suchbyproducts may be unavoidable in the ammonolysis of Formula V, Formula Imay still be obtained in sufficient purity via distillation due to itslower vapor pressure (relative to its oligomeric counterparts). Thepreferred molar proportion of NH₃/Formula V is 20:1, but in variousembodiments, this ratio can be greater than or less than 20:1. While inpreferred embodiments, the reaction is carried out without a solvent, inother embodiments, the reaction may be carried out in a solvent.Non-limiting examples of optional solvents include, independently or incombination, water, methanol, ethanol, and dioxane. The reaction can becarried out in the range from 20° C. to 200° C., and in an embodiment,in the range of 40° C. to 140° C. In an embodiment, the reaction timeand yield may be increased by the addition of additives, such as, butnot limited to, NaI. In an embodiment, upon completion of the reaction,any excess of ammonia can be released. In an embodiment, the ammonia canbe captured for recycling. Formula I can be isolated via distillationafter filtration of NH₄Cl or other salts. In an embodiment, molecularspecies having basic pH characteristics can be added to aid inpurification. In another embodiment, Formula I can be purified via anextraction process and subsequent distillation.

Example 2 Preparation of Formula I Via the Reduction ofdi-(2-nitroethyl) Formal (Formula VI)

The key embodiment of this example is the formation of Formula I via thereduction of di-(2-nitroethyl) formal (Formula VI).

The synthesis of Formula VI can be accomplished via the reaction of2-nitroethanol and formaldehyde (which can be employed in solid form asparaformaldehyde or trioxane) such as using the procedures detailed fordinitro acetal compounds in U.S. Pat. No. 2,415,046 or U.S. 2009/0216049A1. There are a variety of common conditions used by those skilled inthe art for the reduction of aliphatic nitro compounds to thecorresponding amines. The conversion of Formula VI to Formula I may beaccomplished using such protocols. By way of a non-limiting example,such protocols include catalytic hydrogenation reaction using Raneynickel, catalytic hydrogenation reaction using Palladium on carbon(Pd/C), catalytic reduction using Pd/C and ammonium formate in methanol,catalytic hydrogenation using PtO₂, catalytic hydrogenation using otherefficient hydrogenation catalyst for the reduction of aliphatic nitrogroups to their corresponding amines, reduction using iron metal in thepresence of acid, reduction using iron metal/FeCl₃ in the presence ofacid. In an embodiment, the hydrogenation catalyst may be recovered viafiltration after the reaction is complete. In an embodiment, thehydrogenation catalyst may be recycled. In an embodiment, Formula I canbe isolated via distillation. In an embodiment, Formula I can bepurified via an extraction process and can optionally be furtherpurified via distillation.

Example 3 Preparation of Formula I from Ethanolamine and Formaldehydewith Excess Acid

Ethanolamine is an inexpensive feedstock chemical that is readilyavailable in mass quantities. As discussed elsewhere herein, the directreaction of formaldehyde with ethanolamine does not lead to theformation of Formula I. This is because of the increased reactivity ofthe amino group relative to the hydroxyl group. Suitably protectedethanolamine derivatives such as N-(2-hydroxyethyl)phthalimide can beused in place of ethanolamine to obtain Formula I in a two step sequenceas in Scheme 2. In an embodiment, ethanolamine can be successfullyreacted with formaldehyde (which can be employed in solid form asparaformaldehyde or trioxane) to obtain Formula I, provided that thereaction is carried out in an excess of acid (i.e., the molarequivalence of acid:ethanolamine is greater than 1). In an embodiment,when the reaction of ethanolamine with formaldehyde is carried out inthe presence of an excess of strong acid, the reactive lone pair of thenitrogen group in ethanolamine is predominately in the protonated form,effectively inhibiting its ability to react with the aldehyde. In thisway, the hydroxyl group of ethanolamine is then able to react with thealdehyde. Thus, two equivalents of the protonated form of ethanolaminecan react with formaldehyde to yield Formula VII, which is the doublyprotonated salt of I.

In an embodiment, deprotonation of Formula VII with a base then providesFormula I. In a preferred embodiment, ethanolamine is treated with acidprior to the addition of the formaldehyde species. Non-limiting examplesof suitable acids include inorganic acids such as HCl and H₂SO₄, ororganic acids such as p-toluenesulfonic acid or methanesulfonic acid. Inan embodiment, formation of VII can be greatly facilitated by conditionsthat remove the formed water during the reaction. In an embodiment,removal of formed water can be accomplished by the addition of dryingagents such as MgSO₄ to the reaction mixture. In another embodiment,removal of the water is effected via use of Dean-Stark type conditions.The reaction temperature can be in the range from 0° C. to 220° C. In anembodiment, ethanolamine hydrochloride is commercially available and itcan be used in lieu of the in situ protonation of ethanolamine.Ethanolamine hydrochloride is a low melting solid and it can be reactedwith paraformaldehyde (or trioxane) in the melt, and water removed viadistillation. In an embodiment, conversion of Formula VII to Formula Ican be accomplished by removal of any volatiles and by treatment with abase. In an embodiment, Formula I may be further purified via extractiontechniques or by distillation.

Example 4 Preparation of Formula I from Ethanolamine and an Acetal ofFormaldehyde with Excess Acid

The embodiments of this example follow those of Example 3 with thesubstitution of an acetal of formaldehyde (Formula VII) used in place offormaldehyde. Non-limiting examples of suitable acetals include FormulaVII; wherein R=alkyl or substituted alkyl group.

Example 5 Preparation of Formula X Via Catalytic Hydrogenation of theFormal of Ethylene Cyanohydrin (Formula XI)

The key embodiment of this example is the formation of Formula X viacatalytic hydrogenation of the formal of ethylene cyanohydrin (FormulaXI).

The starting compound Formula XI for this transformation can be preparedfrom the reaction of 2 molar equivalents of acrylonitrile with 1 molarequivalents of paraformaldehyde under aqueous reaction conditionsaccording to the procedure detailed in U.S. Pat. No. 2,353,671. The keyreaction of this disclosure is the transformation of the dinitrileFormula XI to the diamine Formula X. In an embodiment, thistransformation may be accomplished using standard reaction protocolsused for the reduction of aliphatic nitrile compounds to theircorresponding amines in the art. In an embodiment, the transformation iscarried out via a catalytic hydrogenation reaction. In an embodiment,the conversion of Formula X to Formula XI may be effected in the liquidphase employing a suitable active hydrogenation catalyst. In anembodiment, conventional hydrogenation catalysts include as the activecomponent a noble metal from the group Ru, Rh, Pd, and Pt, or atransition metal the group Cu, Cr, Co, Ni, Fe, including, but notlimited to, Raney catalysts and chromite catalyst. In an embodiment,bimetallic catalysts of one or more transition metals and/or noblemetals may also be used. One of skill in the art, when viewing thepresent disclosure, will understand how to select a catalyst, includingconsiderations of the useful life of any particular catalyst. In anembodiment, an example of a preferred catalyst is Raney Ni. In anembodiment, the hydrogenation can be conducted in the liquid or vaporphase at temperatures ranging between 20° C. and 200° C. and atpressures of 1 and 1000 atmospheres, and in another embodiment, in thetemperate range between 60° C. and 150° C. and under pressures between10 and 110 atmospheres. In an embodiment, the conversion of Formula X toFormula XI may be enhanced by the presence of ammonia during thereaction. In an embodiment, from 1 to 20 moles of ammonia per mole ofFormula X is used. In an embodiment, hydrogenation of Formula XI can becarried out using anhydrous ammonia. In an embodiment, hydrogenation iscarried out in aqueous ammonia, or in a suitable solvent such as, butnot limited to, for example, methanol, ethanol, dioxane, or any solventthat is not substantially hydrogenated during the reaction or decomposedby the added ammonia. Upon the completion of the reaction, the catalystcan be removed via filtration and Formula X can be obtained afterremoval of any solvents. In an embodiment, Formula X can be furtherpurified via distillation under reduced pressure.

It will be appreciated by those skilled in the art that changes could bemade to the exemplary embodiments shown and described above withoutdeparting from the broad inventive concept thereof. It is understood,therefore, that this invention is not limited to the exemplaryembodiments shown and described, but it is intended to covermodifications within the spirit and scope of the present invention asdefined by the claims. For example, specific features of the exemplaryembodiments may or may not be part of the claimed invention and featuresof the disclosed embodiments may be combined. Unless specifically setforth herein, the terms “a”, “an” and “the” are not limited to oneelement but instead should be read as meaning “at least one”.

It is to be understood that at least some of the descriptions of theinvention have been simplified to focus on elements that are relevantfor a clear understanding of the invention, while eliminating, forpurposes of clarity, other elements that those of ordinary skill in theart will appreciate may also comprise a portion of the invention.However, because such elements are well known in the art, and becausethey do not necessarily facilitate a better understanding of theinvention, a description of such elements is not provided herein.

Further, to the extent that the method does not rely on the particularorder of steps set forth herein, the particular order of the stepsshould not be construed as limitation on the claims. The claims directedto the method of the present invention should not be limited to theperformance of their steps in the order written, and one skilled in theart can readily appreciate that the steps may be varied and still remainwithin the spirit and scope of the present invention.

I claim:
 1. A process for preparing a compound represented by Formula(1) from a compound of Formula (2):

wherein: each of R¹ and R² is independently selected from the groupconsisting of hydrogen, alkyl group, cycloalkyl group and aromaticgroup; or both of R¹ and R² forms a cyclic radical; each of R³, R⁴, R⁵,and R⁶ is independently selected from the group consisting of hydrogen,alkyl group, cycloalkyl group and aromatic group; R³ and R⁴ can combinewith each other to form a cyclic radical; R⁵ and R⁶ can combine witheach other to form a cyclic radical; and each m and n is independentlyan integer ranging from 1 to 20; the process comprising reducing thecompound of Formula (2) with a reducing agent to produce the compound ofFormula (1).
 2. The process of claim 1, wherein the reducing agentcomprises molecular hydrogen.
 3. (canceled)
 4. The process according toclaim 3, wherein the catalyst is recycled.
 5. The process of claim 1,wherein the reduction is carried out in the presence of ametal-containing catalyst. 6-7. (canceled)
 8. The process of claim 1,wherein the reduction is carried out in the presence of a catalyst and acatalyst promoter. 9-12. (canceled)
 13. The process of claim 1, whereinthe reduction is carried out at a temperature of from about 15° C. toabout 200° C.
 14. (canceled)
 15. The process of claim 2, wherein thereduction is carried out at molecular hydrogen pressure of from about 80psi to about 3000 psi. 16-20. (canceled)
 21. The process of claim 1,wherein the reduction is carried out in the presence of ammonia.
 22. Theprocess of claim 1, wherein the reduction is carried out in the presenceof anhydrous ammonia.
 23. The process of claim 1, wherein the reductionis carried out in the presence of aqueous ammonia.
 24. The process ofclaim 21, wherein the ammonia is recycled ammonia.
 25. The process ofclaim 1, wherein the reduction is carried out in the presence ofammonia, the ammonia being present in an amount of from about 1 mole toabout 40 moles per mole of the compound of Formula (2) used.
 26. Theprocess of claim 1, wherein the reduction is carried out in the presenceof a solvent. 27-28. (canceled)
 29. The process according to claim 1,wherein the reduction is carried out in a batch reactor.
 30. The processaccording to claim 1, wherein the reduction is carried out in acontinuous reactor.
 31. The process according to claim 30, wherein thecontinuous reactor is selected from the group consisting of a flowreactor, a continuous stirred tank reactor, a trickle bed reactor, aloop reactor, a bubble reactor, a tube reactor, a pipe reactor, and aslurry reactor.
 32. The process according to claim 1, wherein thecompound of Formula (2) is selected from the group consisting of:


33. The process according to claim 1, wherein the compound of Formula(1) is selected from the group consisting of:

34-75. (canceled)